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Chemistry Perfect Score Module 2012 1 BAHAGIAN PENGURUSAN SEKOLAH BERASRAMA PENUH DAN SEKOLAH KECEMERLANGAN MODUL PERFECT SCORE & X A-PLUS SEKOLAH BERASRAMA PENUH TAHUN 2012 PANEL PENYEDIA DAN PEMURNI: Pn. Wan Noor Afifah Binti Wan Yusoff (Ketua) SBPI GOMBAK Tn Hj Ja'afar B Bajuri SMS SULTAN MAHMUD Pn. Norini Binti Jaafar SEKOLAH SULTAN ALAM SHAH Tn Hj Che Malik Bin Mamat SBPI BATU RAKIT Pn. Rossita Binti Radzak SMS TUANKU MUNAWIR En Jong Kak Ying SMS KUCHING En Ooi Yoong Seang SMS MUAR Che Ramli B Che Ismail SMS FARIS PETRA Pn Masodiah Bt Mahfodz SMS HULU SELANGOR Pn. Noraini Binti Zakaria SMS SULTAN MOHAMAD JIWA

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Chemistry Perfect Score Module 2012 1

BAHAGIAN PENGURUSAN SEKOLAH BERASRAMA PENUH

DAN SEKOLAH KECEMERLANGAN

MODUL PERFECT SCORE &

X A-PLUS

SEKOLAH BERASRAMA PENUH TAHUN 2012

PANEL PENYEDIA DAN PEMURNI:

Pn. Wan Noor Afifah Binti Wan Yusoff (Ketua) SBPI GOMBAK

Tn Hj Ja'afar B Bajuri SMS SULTAN MAHMUD

Pn. Norini Binti Jaafar SEKOLAH SULTAN ALAM SHAH

Tn Hj Che Malik Bin Mamat SBPI BATU RAKIT

Pn. Rossita Binti Radzak SMS TUANKU MUNAWIR

En Jong Kak Ying SMS KUCHING

En Ooi Yoong Seang SMS MUAR

Che Ramli B Che Ismail SMS FARIS PETRA

Pn Masodiah Bt Mahfodz SMS HULU SELANGOR

Pn. Noraini Binti Zakaria SMS SULTAN MOHAMAD JIWA

Chemistry Perfect Score Module 2012 2

CHEMISTRY PERFECT SCORE MODULE 2012

CONTENT

1 Guidelines &

Anwering Techniques

Format of an instrument of chemistry Construct requirement Guidelines for answering paper 1 Guidelines for answering paper 2 Guidelines for answering paper 3 The common command words in paper 2

2 Set 1

The structure of Atom Chemical Formulae and equations Periodic Table of Elements Chemical Bonds

3 Set 2 Electrochemistry Oxidation and Reduction

4 Set 3

Acids and Bases Salts Rate of reaction Thermochemistry

5 Set 4 Carbon compounds Manufactured Substance in Industry Chemicals for Consumers

6 Set 5 Paper 3 set 1 Paper 3 set 2 Paper 3 set 3

Chemistry Perfect Score Module 2012 3

CHEMISTRY

PERFECT SCORE MODULE

GUIDELINES

&

ANSWERING TECHNIQUES

CHEMISTRY SPM

Chemistry Perfect Score Module 2012 4

GUIDELINES AND ANSWERING TECHNIQUES FOR SPM CHEMISTRY PAPER

1.0 FORMAT OF AN INSTRUMENT OF CHEMISTRY BEGINNING SPM 2003

No Item Paper 1

(4541/1)

Paper 2

(4541/2)

Paper 3

(4541/3)

1 Type of instrument Objective test Subjective test Written Practical Test

2

Type of item Objective it Section A :

Structured Item

Section B :

Essay restricted response Item

Section C :

Essay extended response Item

Subjective Item :

Structured Item

Extended Response Item:

(Planning an experiment)

3

Number of

question

50 (answers all) Section A : 6 (answer all)

Section B : 2 (choose one)

Section C : 2 (choose one)

Structured Item :

1/2 items (answer all)

Extended Response Item :

1 item

5 Duration of time 1 hour 15

minutes

2 hour 30 minutes 1 hour 30 minutes

2.0 CONSTRUCT REQUIREMENT

Construct Paper 1 Paper 2 Paper 3

Knowledge 20 m ( No 1- 20) 14 -

Understanding 15 m ( No 21 – 35) 21 -

Application 15 m ( No 36 – 50) 29 -

Analysis - 21 -

Synthesizing - 15 -

Science process - - 50

Total mark 50 100 50

3.0 TIPS TO SCORE “ A “ CHEMISTRY

3.1 Master the topics that contains the basic concepts of chemistry :

1. The structure of the atom

2. Chemical Formulae And Equations

3. Periodic Table

4. Chemical Bond

3.2 Familiarize with different types of questions as listed below and complete the previous SPM

papers:

1. Objectives questions (MCQ) (Paper 1)

2. Structured questions ( Paper 2 & 3)

3. Essays (Paper 2)

4. Planning an experiment ( Paper 3)

5. Draw and label the diagram

6. Writing chemical equation( balanced equation, ionic equation, half equation)

3.3 Try to get :-

40 marks above for paper 1

60 marks above for paper 2

40 marks above for paper 3 (Total = 180/2 =80 , A+ in SPM)

Chemistry Perfect Score Module 2012 5

4.0 GUIDELINE FOR ANSWERING PAPER 1

4.1 Paper 1 questions test students on

1. Knowledge ( Number 1 – 20)

2. Understanding ( Number 21 – 35)

3. Application ( Number 36 – 50 )

4.2 Score in paper 1 Indicates student’s level of understanding in chemistry:

Less than 20 – very weak

20 – 25 - weak

26 – 30 - average

31 – 39 - good

40 – 45 - very good

46 – 50 - excellent.

4.3 Answer all SPM objective questions (2003 – 2010). Objective questions for each year contain all

topics. If your score in paper 1 is 40 and above, you will able to answer questions in paper 2 & 3

easily.

5.0 GUIDELINE FOR ANSWERING PAPER 2 (STRUCTURE AND ESSAY)

5.1 Paper 2 questions test student on

1. Knowledge

2. understanding

3. analyzing

4. synthesizing

5.2 Steps taken are:

1. Underline the command word and marks allocated for each question.

2. Match the command word to the mark allocated for each question. 1 point is awarded 1

mark.

3. Follow the needs of the question (Refer to the command words, page …….)

4. Unnecessary repetition of the statement in the question is not required.

5.3 Three types of questions which involve experiments in paper 2:

I. Type 1

Describe an experiment on…………………Include a labeled diagram in your answer

1. Diagram

2. Procedure

3. Observation/example/data/calculation/equation/sketch of graph/conclusion

II. Type 2

Describe an experiment……………( The diagram will support your answer.)

1. No mark is allocated for a diagram

2. Procedures

3. Observation/example/calculation/equation/sketch of graph/conclusion

III. Type 3

Describe a chemical/confirmatory test for …….

1. Procedure

2. Observation

3. Conclusion

6.0 GUIDELINE FOR ANSWERING PAPER 3

6.1 Structure Question 1/2 test the mastery of 11 Scientific Skills

1. Observing

2. Classifying

3. Inferring

4. Measuring (burette , stopwatch, thermometer, voltmeter)

5. Predicting

6. Communicating( e.g construct table and draw graph)

7. Space-Time Relationship

8. Interpreting Data

Chemistry Perfect Score Module 2012 6

9. Defining Operationally

10. Controlling Variables

11. Hypothesizing

Each answer is allocated mark as follows: 3 marks/2 marks/1 mark/0 Score : 11 X 3 = 33

Example of operational definition:

1. what you do

2. what you observe correctly

Example:

1. When acid is added into latex, white solid is formed.

When acid is added into latex, latex coagulated.- wrong

2. When the higher the concentration sodium thiosulphate solution is added into sulphuric acid, time taken for

`X~ mark to disappear from sight is shorter.

3. When iron nail is coiled with copper and immersed into jelly mixed with potassium hexacyanoferrate(III) and

phenolphthalein solution, blue spot/colouration is formed.

Operational definition for What you do What is observed

1. Rusting of iron When an iron nail coiled with a less

electropositive metal is immersed in hot

agar-agar added with potassium

hexacyanoferrate (III) solution,

Blue spots are formed

2. Coagulation of latex When acid is added to latex White solid is formed

3. Reactivity of Group 1

elements

When a metal which is lower in Group 1 is

put in a basin half filled with water

Brighter flame is formed

4. Precipitation of silver

chloride

When silver nitrate solution is added to

sodium chloride solution

White solid is formed

5. Voltaic cell When two different metals are dipped into an

electrolyte

The needle of the voltmeter

deflects

6. An acid When a blue litmus paper is dipped into a

substance which is dissolved in water,

Blue litmus paper turns red

Hypothesis: Relate manipulated variable followed by responding variable with direction.

Example:

1. The higher temperature of the reactant the higher the rate of reaction – 3 marks

The temperature of the reactant affect the rate of reaction – 2 marks

2. Hexene decolourised brown bromine water but hexane does not decolourised brown bromine water.

3. When acid is added into latex, latex coagulates, when ammonia is added into latex, latex cannot coagulates

4. Question 3 (essay) Test The Mastery of Planning Experiment .

Planning should include the following aspects:

1. Aim of the experiment/Statement of the problem

2. All the variables

3. Statement of the hypothesis

4. List of substances/material and apparatus – should be separated

5. Procedure of the experiment

6. Tabulation of data Score : (5 X 3) + 2 = 17

The question normally starts with certain situation related to daily life.

Problem statement/ aim of the experiment / hypothesis and variable can be concluded from the situation given.

State all the variables

Manipulated variable :

Responding variable :

Constant variable: list down all the fixed variables to ensure the outcome of the responding variable is

related only to the manipulated variables.

Chemistry Perfect Score Module 2012 7

Separate the substances and apparatus

- Separate the substances and apparatus

- Apparatus : list down the apparatus for the experiment.

Example: Rate of reaction – stop watch

Termochemistry - thermometer

Procedure :

All the steps taken in the procedure must include the apparatus used, quantity and type of substance (powder,

solution, lumps … etc).

No mark is allocated for the diagram. The complete labeled diagram can help students in :

I. Writing the steps taken in the procedure

II. Listing the apparatus and materials

Tabulation of data:

The number of columns and rows in the table is related to the manipulated and responding

variables

Units must be written for all the titles in each row and column of the table

DO NOT WRITE the observation/inference/conclusion in the table.

7.0 THE COMMON COMMAND WORDS IN PAPER 2 & PAPER 3 CHEMISTRY

The question normally starts with a command word.

Students must know the meaning of the command word to make sure that the answer given is according

to the question’s requirement.

Match the command word to the mark allocated for each question.

Command word Explanation/example

Name/State the

name

(paper 2 & 3)

Give the name , not the formula.

Example: Name the main element added to copper to form bronze.

Wrong answer : Sn.

Correct answer : Tin

State

(paper 2 & 3)

Give brief answer only. Explanation is not required.

Example : State one substance which can conduct electricity in solid state.

Answer : Copper

State the

observation

(Paper 2 & 3)

Write what is observed physically.

Example 1 : State one observation when magnesium powder is added to hydrochloric

acid. [ 1 mark]

Wrong answer : Hydrogen gas is released.

Correct answer : Gas bubbles are released

Indicate the change of colour , give the initial and final colour of the substance/chemical.

Example 2: What is the colour change of copper(II) suphate solution. [2 marks]

Wrong answer: The solution becomes colourless

Correct answer : The blue colour of the solution becomes colourless

Explain

(Paper 2 & 3)

Give the answer with reasons to explain certain statement / fact / observation/ principal.

Example 1 : Explain why bronze is harder than pure copper [4 marks]

Correct answer :

- Copper atoms in pure copper are all of the same size and ...........1

- they are arranged in layers that can slide easily when force is applied ...........1

- The presence of tin atoms in bronze that are different in size disturb the

orderly arrangement of atoms in bronze. ...........1

- This reduces the layer of atoms from sliding. ...........1

What is meant by..

(Definition)

(Paper 2 & 3)

Give the exact meaning

Example: What is meant by hydrocarbon.

Wrong answer: A compound that contains carbon and hydrogen

Correct answer: A compound that contains carbon hydrogen only

Describe chemical

test

(Paper 2 & 3)

State the method to conduct the test , observation and conclusion.

Example : Describe how to identify the ion present in the solution . [3 marks]

Answer : - Pour in 2 cm3 of the solution in a test tube. Add a few drops of sodium

hydroxide solution and the test tube is shake the test tube ...........1

Chemistry Perfect Score Module 2012 8

- A reddish brown precipitate formed. ...........1

- Fe3+

ions present ………1

Describe gas test.

(Paper 2 & 3)

State the method to conduct the test observation and conclusion.

Example: Describe the confirmatory test for gas released at the anode (oxygen). [3 marks]

Wrong answer: Test with a glowing wooden splinter.

Correct answer: - Place a glowing wooden splinter to the mouth of the test tube ..…….1

- The glowing wooden splinter is lighted up ...……1

- Oxygen gas is released ..…….1

Describe an

experiment

( 8 - 10 marks)

(Paper 2)

- No mark is awarded for the diagram. The diagram can help students write the steps

taken in the procedure.

- List of materials 1m

- List of apparatus 1m

- Procedure ( 5 – 8 m)

- Observation/tabulation of data/ calculation/sketch of the graph/ chemical equation /ionic

equation /conclusion …… etc.

- Any additional details relevant derived from the question.

Plan an

experiment

( 17 marks)

( Paper 3)

Answer the question according the requirement :

Problem statement/Aim of experiment

Hyphotesis

Variables

List of substances and apparatus

Procedure

Tabulation of data

Note: For question 3, unlike PEKA report students only need to answer according to what is

stated in the question.

- No mark for the diagram. Diagram can help student writing the steps taken in the

procedure.

Describe the

process …

Describe the

structure ….

Describe and

write equation…

Describe how …

(Paper 2 & 3)

Give relevant details derived from the question.

Predict

(Paper 2 & 3)

Make a prediction for something that might happen based on facts

Example: Experiment 1 is repeated using a larger beaker. Predict the increase in

temperature

Answer : The increase in temperature is lower than experiment 1.

Compare

(Paper 2)

Give the similarities and differences between two items/ situations

Differentiate

(Paper 2)

Give differences between two items/situations

Example : State three differences between ionic and covalent compound.

Answer : State three properties of ionic compound and three properties covalent compound

Draw a labeled

diagram of the

apparatus

(Paper 2)

Draw a complete set up of apparatus

(i) Functional set up of apparatus

(ii) Complete label

(iii) Shade solid, liquid and gas correctly.

(iv) Draw an arrow and label ’ heat’ if the experiment involves heating

Draw a diagram

to show the

bonding formed in

the compound

(Paper 2)

(i) Ionic compound – The number of electrons in each shell is correct, 2 electrons in

the first shell

and 8 electrons in the second and third shell.

– Show the charge of each particle.

– Write the symbol of each element at the centre of the ion.

(ii) Covalent compound

The number of electrons in each shell is correct, 2 electrons in the first

shell and 8 electrons in the second and third shell.

The number of atoms sharing pair of electrons is correct.

Can be obtained from the diagram

Chemistry Perfect Score Module 2012 9

Write the symbol of each element at the center of each atom in the

molecule.

Draw graph

(Paper 3)

Draw graph as follows :

Label the two axis with the correct unit

Choose suitable scale, the size of the graph should be at least ¾ of the size of the

graph paper.

Plot all the points correctly

Smooth graph ( curve or straight line )

For the determination of the rate of reaction

(i) Draw a tangent at the curve.

(ii) Draw a triangle at the tangent

Calculate the gradient of the tangent

Draw the energy

level diagram

( Paper 2)

Draw an arrow for the vertical axis only and label with energy.

Draw two horizontal lines for the reactants and products

Draw the

arrangement of

particles in solid,

liquid and gas.

(Paper 2)

Solid: Draw at least three layers of particles closely packed in orderly manner and

they are not overlap.

Liquid : The particles packed closely but not in orderly manner

Gas : The particles are very far apart from each other

Draw the direction

of electron flow

(Paper 2 /3)

Draw the direction for the flow of electrons on the circuit, not through the solution.

Write chemical

equation

(Paper 2 & 3)

Write the balanced chemical equation

Differentiate :

(i) Balanced chemical equation

(ii) Ionic equation

(iii) Half equation for oxidation

(iv) Half equation for reduction

Calculate

(Paper 2 & 3) Show all the steps taken

Give final answer with unit.

Classify

(Paper 3) Draw table to represent the classification.

Chemistry Perfect Score/X A-Plus Module 2012 11

SECTION A

1. Table 1 shows the proton number and nucleon number for atoms L, M and N.

Atom Proton number Nucleon number

L 16 32

M 17 35

N 17 37

Table 1

(a) (i) What is meant by proton number ?

………………………………………………………………………………………

[1 mark ]

(ii) What is the number of neutrons in atom M ?

………………………………………………………………………………………

[1 mark ]

(b) Which atoms are isotopes ? Explain your answer.

………………………………………………………………………………………

………………………………………………………………………………………

[2 marks]

(c) (i) Write the electron arrangement for atom L.

………………………………………………………………………………………

[1 mark ]

(ii) State the position of atom L in the Periodic Table

…………………………………………………………………………………

[1 mark ]

(iii) Explain your answer in c (ii)

…………………………………………………………………………………..

…………………………………………………………………………………….

[2 marks ]

(d) Write the formula of ion formed from atom M

………………………………………………………………………………………

[1 mark ]

Chemistry Perfect Score/X A-Plus Module 2012 12

2 Diagram 2 shows part of the Periodic Table of Elements.T, U, V, W, X, Y and Z do not represent the

actual symbol of the elements.

1 18

2 13 14 15 16 17

V X W Z

U Y

T

Diagram 2

(a) Write the electron arrangement of U atom.

…………………………………………………………………….............................

[1 mark ]

(b) (i) Which of the element exist as a monoatomic gas ?

…….......................................................................................................................

[1 mark ]

(ii) Explain your answer in (b)(i).

………….…………………………………………………………………………………….

. ………………..............................................................................................................

[2 marks ]

(c) V reacts with W to form a compound.

(i) Write the formula for the compound formed.

………………………………………………………………………………………

[1 mark ]

(ii) Draw the electron arrangement for the compound formed in (c)(i).

[2 marks ]

(d) (i) Choose an element that is a halogen.

……………………………………………………………………………………

[1 mark ]

(ii) Which element forms an amphoteric oxide ?

…….………………………………………………………………………………

[1 mark]

(iii) Choose the element which form a coloured ion or compound

…………………………………………………………………………………….

[1 mark ]

Chemistry Perfect Score/X A-Plus Module 2012 13

3 Table 3 shows the element in Period 3 with their respective proton numbers.

Element Na Mg Al Si P S Cl Ar

Proton number 11 12 13 14 15 16 17 18

Table 3

(a) (i) Write the electron arrangement of sulphur atom,

[1 mark ]

(ii) In which group of the Periodic Table is Sulphur, S located ?

.....................................................................................................................................

[1 mark ]

(b) (i) How does the atomic size change when going across the Period from left to right ?

............................................................................................................................. ..............

[1 mark ]

(ii) Explain your answer in 2(b)(i)

...........................................................................................................................................

............................................................................................................................. ...............

[2 marks ]

(c) Argon, Ar is chemically unreactive. Explain why ?

............................................................................................................................. ................

............................................................................................................................................

[2 marks ]

(d) Which of the element when reacts with oxygen produces an amphoteric oxide ?

…………...........................................................................................................................

[1 mark ]

(e) Write the chemical equation when sodium react with water.

............................................................................................................................. ............

[2 marks ]

4. Table 4 shows the electron arrangement of atoms of elements J,K,L,M and N.

Element Electron arrangement of atom

J 1

K 2.8.1

L 2.8.6

M 2.8.7

N 2.8.8

Table 4

(a) State one element in Table 4 which is metal and non-metal?

Metal : .......................................................................................................

Non- metal : ........................................................................................................

[2 marks]

Chemistry Perfect Score/X A-Plus Module 2012 14

(b) (i) State an element that exist as a diatomic gas. Explain your answer.

....………………………………………………………………………………………..

[1 mark ]

(ii) Explain your answer in (b)(i)

……………………………………………………………………………………....

[3 marks]

(c) (i) What is the Proton Number for atom M

............................................................................................................................. .........

[1 mark ]

(ii) Which group is atom M located in the Periodic Table ? Explain your answer.

.....................................................................................................................................

....................................................................................................................................

[2 marks ]

(d) Arrange atoms K, L and M in increasing atomic size

.......................................................................................................................................

[1 mark ]

(e) Write the formula for K ion.

......................................................................................................................................

[1 mark ]

(f) K and M react to form an ionic compound.State the formula for this compound.

.....................................................................................................................................

[1 mark ]

5 (a) Table 5 shows three substances and their respective chemical formulae.

Name of substance Chemical formula

Chlorine Cl2

Magnesium Mg

Magnesium chloride MgCl2

Table 5

Use information from Table 1 to answer the following questions :

(i) State one substance which exists as an atom.

…………………………………………………………………….…………………….[1 mark]

(ii) Write the ionic formula for the substance in (a) (i).

…………………………………………………………………….…………………….

[1 mark]

(iii) Which substance has the lowest melting point?

…………………………………………………………………….…………………….

[1 mark]

Chemistry Perfect Score/X A-Plus Module 2012 15

(iv) What is the state of matter of chlorine at room temperature?

…………………………………………………………………….…………………….

[1 mark]

(v) Magnesium chloride can conduct electricity in aqueous solution. Give a reason.

…………………………………………………………………….…………………….

[1 mark]

(b) Graph 1 shows the temperature against time when molten of acetamide, C2H5NO is cooled.

Graph 1

(i) State the type of compound of acetamide.

..........…………………………………………………………………………………

[1mark]

(ii) State the melting point of acetamide.

……………….…………………………………………………………………………

[1 mark]

(iii) Describe the movement of the particles of acetamide between A and B during cooling.

…………………………………………………………………………………………

[1 mark]

(iv) Draw the arrangement of particles of acetamide at stage CD.

[1 mark]

Temperature / 0C

Time / s

T1

T2

T3

A

B C

D

Chemistry Perfect Score/X A-Plus Module 2012 16

Heat

6 (a) In a close container, contains 3.0 dm3 of carbon dioxide gas at room temperature.

(i) How many molecules are there in 3.0 dm3 of carbon dioxide gas, CO2 ?

[Avogadro’s number = 6.02 x 1023

mol-1

]

[1 mole of gas occupies 24 dm3 at room temperature]

Use: Number of mole = Number of particles

6.02 x 1023

mol-1

[2 marks]

(ii) Calculate the mass of carbon dioxide gas in the container

[Relative molecular mass for CO2 = 44]

Use: Number of mole = mass

molar mass

[1 mark]

(b) Diagram 6 shows the set-up of apparatus for an experiment to determine the empirical formula

of magnesium oxide..

Diagram 6

Table 1 shows the results of this experiment

Description Mass (g)

Mass of crucible + lid 34.0

Mass of crucible + lid + magnesium ribbon 36.4

Mass of crucible + lid + magnesium oxide 38.0

Table 1

(b) (i) What is the meaning of emperical formula

…………………………………………………………………………………….

…………………………………………………………………………………..

[1 mark]

Magnesium ribbon

Chemistry Perfect Score/X A-Plus Module 2012 17

(ii) Base on table 1, calculate the mass of:

Magnesium :

Oxygen :

[2 marks]

(iii) Calculate the ratio of mole of magnesium atoms to oxygen atoms.

[Relative atomic mass: O=16, Mg =24]

[1 mark]

(iv) Determine the empirical formula of magnesium oxide.

[1 mark]

(v) Why was the crucible lid opened once in a while during the experiment?

…………..………………………………………………………………………..

[1 mark]

(v) State why the empirical formula of copper oxide cannot be determine by using the same

technique.

…………..………………………………………………………………………..

[1 mark]

7. (a) What is the meaning of molecular formula?

……………………………………………………………………………………...

……………………………………………………………………………………..

[1 mark]

(b) Diagram 7.1 shows an incomplete equation which is one of the steps involved in determining the

empirical formula.

Complete this equation.

Diagram 7.1

Mass

Relative atomic mass = ……………………………

Chemistry Perfect Score/X A-Plus Module 2012 18

(c) Diagram 7.2 shows the apparatus set-up for two methods used to determine the empirical formula

of two compounds.

Method 1 Method II

Diagram 7.2

(i) Which method is suitable to be used to determine the empirical formula of magnesium oxide?

………………………………………………………………………………….……………

[1 mark]

(ii) Why did you choose the method in 2(c)(i)?

……………………………………………………………………………….……………

[1 mark]

(iii) When carrying out an experiment using Method I, why does the crucible lid need to be opened

once a while?

………………………………………………………………………………………………

………………………………………………………………………………………………

[1 mark]

(d) Diagram 7.3 shows the results for an experiment to determine the empirical formula of lead oxide.

Diagram 7.3

Based on Diagram 2.3, determine the values of the following

[Relative atomic mass of O =16 , Pb = 207]

(i) Mass of lead

= ………………………… g

[1 mark]

(ii) Number of moles of lead.

= ……………………………mol

[1 mark]

(iii) Mass of oxygen

= …………………………..g

[1 mark]

(iv) Number of moles of oxygen.

= ……………………………mol

[1 mark]

(v) Empirical formula of oxide of lead.

= ……………………………

[1 mark]

Mass of combustion tube + porcelain dish = 54.00 g

Mass of combustion tube + porcelain dish + lead oxide = 107.52 g

Mass of combustion tube + porcelain dish + lead = 103.68 g

Chemistry Perfect Score/X A-Plus Module 2012 19

8. Diagram 8 shows the apparatus set-up to determine the empirical formula of copper oxide.

Diagram 8

Table 8 shows the result of this experiment.

Description Mass(g)

Combustion tube + porcelain dish 42.25

Combustion tube + porcelain dish + copper oxide 52.25

Combustion tube + porcelain dish + copper 50.25

Table 8

(a) (i) What is the meaning of empirical formula?

………………………………………………………………………………………

………………………………………………………………………………………

[1 mark]

(ii) State the function of the anhydrous calcium chloride.

………………………………………………………………………………………..

[1 mark]

(b) (i) Based on Table 8, determine the mass of:

Copper:

=………………………………..g

Oxygen:

= ………………………………..g

[2 marks]

(ii) Calculate the ratio of moles of copper atoms to oxygen atoms.

[Relative atomic mass: O = 16 ; Cu = 64]

[1 mark]

Chemistry Perfect Score/X A-Plus Module 2012 20

(iii) Determine the empirical formula of copper oxide.

………………………………………………………………………………………

[1 mark]

(c) (i) Why is hydrogen gas passed through the combustion tube after heating has

stopped?

……………………………………………………………………………………….

……………………………………………………………………………………….

[1 mark]

(ii) State how to determine that the reaction between copper oxide with hydrogen has

completed.

………………………………………………………………………………………

………………………………………………………………………………………

[1 mark]

(d) (i) State why the empirical formula of magnesium oxide cannot be determined by

using the same technique.

……………………………………………………………………………………

……………………………………………………………………………………

[1 mark]

(ii) State the name of another metal oxide whose empirical formula can be

determine using the same technique.

…………………………………………………………………………………..

[1 mark]

SECTION B

9 (a) Diagram 9.1 shows the atomic structure of two carbon isotopes.

Diagram 9.1

(a) Compare the two isotopes above in terms of number of proton, number of electron, nucleon

number,physical properties and chemical properties.

[6 marks]

Nucleus

6 neutrons

Nucleus

8 neutrons

Chemistry Perfect Score/X A-Plus Module 2012 21

(b) Diagram 9.2 shows the set up of apparatus used in experiment to determine the melting

points of X.

Diagram 9.2

(i) Suggest one example of substance X.

[1 mark]

(ii) State the name of P. Explain why P is used?

[2 marks]

(iii) Graph 9 shows the heating curve of X.

Graph 9

Describe Graph 9 in terms of state of matter, particles arrangement, kinetic energy of

particles and attraction forces between particles.

[10 marks]

(iv) After t3 minutes, X is cooled at room temperature. Sketch a graph of temperature

against time for cooling process.

.

[2 marks]

Temperature / 0C

Suhu / 0C

Time/

minutes

Masa / minit

100

30

t1 t2 t3

80

0

Q

X

Heat

P

Chemistry Perfect Score/X A-Plus Module 2012 22

10 (a) Helium, He4

2 exists as a monoatomic gas whereas chlorine, Cl35

17 exists as a diatomic gas.

Explain why.

[6 marks]

(b) Table 10.1 shows the proton number of magnesium, chlorine and carbon.

Element

Magnesium Chlorine Carbon

Proton number 12 17 6

Table 10.1

(i) Carbon reacts with chlorine to form a compound.

What type of the compound formed?

Draw the electron arrangement to show the chemical bond in the compound.

[3 marks]

(ii) Explain how ionic bond is formed between magnesium and chlorine atoms.

[7 marks]

(c) Diagram 10 shows the set-up of apparatus to investigate the electrical conductivity of

naphthalene and sodium chloride solution.

Diagram 10

Table 10.2 shows the result of the experiments.

Compound Observation

Naphthalene Bulb does not light up

Sodium chloride solution

Bulb lights up

Table 10.2

Explain the electrical conductivity of the two compounds.

[4 marks]

Bulb

Carbon

electrode

Compound

Chemistry Perfect Score/X A-Plus Module 2012 23

Empirical formula is CH2O.

Relative molecular mass is 60.

Reacts with calcium carbonate to produce a type of gas that turns lime

water chalky.

11. (a) The following are the formulae of two compounds.

Al2O3 PbO2

(i) Based on the two formulae, write the formula for ion aluminium and ion lead

[2 marks]

(ii) Name both compounds based on the IUPAC nomenclature system.

[2 marks]

(b) The following information is about an organic compound, K.

Based on the information given:

(i) Determine the molecular formula of K.

[Relative atomic mass : H = 1, C = 12, O = 16]

[3 marks]

(ii) Write a balanced chemical equation for the reaction of compound K with calcium carbonate.

[2 marks]

(c) Diagram 11 shows the apparatus set up for experiment of decomposition of copper(II) carbonate. In this

experiment copper(II) oxide and carbon dioxide gas are formed.

Based on Diagram 11

(i) State two observations.

[2 marks]

(ii) Write a balanced chemical equation for the reaction

[2 marks]

(iii) ) State two informations from the chemical equation in (c)(ii).

[2 marks]

Diagram 11

Copper(II) carbonate powder

Lime water

Heat

Chemistry Perfect Score/X A-Plus Module 2012 24

(v) Calculate the mass of the copper(II) oxide formed from the decomposition of 12.4 g of

copper(II) carbonate.

[ Relative atomic mass of C = 12; O = 16; Cu = 64]

[3 marks]

(vi) In other experiment 4.0 g copper(II) oxide is reacted with hydrogen gas to produce copper and water.

If the mass of copper in copper(II) oxide is 3.2 g, calculate the mass of oxygen and the simplest mole

ratio for the copper atoms to oxygen atoms

[ Relative atomic mass of O = 16; Cu = 64]

[2 marks]

12. Table 12 shows the positive and negative ions in three salts solution.

Name of salt Positive ion Negative ion

Iron(III) chloride Fe3+

Cl-

Potassium sulphate K+ SO4

2-

Lead(II) nitrate Pb2+

NO3-

Table 12

Use the information in Table 12 to answer the following questions.

(a) (i) What are another name for a positively charged ion and negatively charged ion?

[2 marks]

(ii) Name the ions in iron(III) chloride.

[2 marks]

(iii) Write the formula for potassium sulphate.

[1 mark]

(b) When 10 cm3 of 0.5 mol dm

-3 potassium sulphate solution is added to excess lead(II) nitrate

solution, a white precipitate is formed.

(i) Name the white precipitate and write the chemical equation for the reaction.

[3 marks]

(ii) Describe the chemical equation in (b)(i).

[1 mark]

(iii) Calculate the mass of precipitate formed.

[Relative atomic mass of O = 16; S = 32; Pb = 207]

[4 marks]

(c) The information below is regarding an organic compound Z.

Relative molecular mass is 46

Carbon : 52.2%

Hydrogen : 13.0%

Oxygen : 34.8%

Relative atomic mass of H = 1; C = 12 and O = 16

Based on the information of the organic compound Z:

(i) Determine the molecular formula for compound Z and [6 marks]

(ii) Draw its structural formula.

[1 mark]

Chemistry Perfect Score/X A-Plus Module 2012 25

SECTION C

13 (a) An experiment is carried out using Group 1 elements; X, Y and Z react with oxygen

gas.The set-up of apparatus and observations of the reaction are shown in Table 13.

Set Set-up of apparatus Observation

I

Burns slowly and

white fumes formed

II

Burns vigorously and

white fumes formed

III

Burns rapidly and

white fumes formed

Table 13

(i) Based on the observation in Table 13, compare the reactivity of element X and Y.

Explain your answer.

[5 marks]

(ii) Suggest the name of element Z. Using the symbol of element suggested, write the

chemical equation for the reaction in set III.

[3 marks]

(b) State how elements of Group 1 are stored in laboratory and give a reason.

[2 marks]

(c)

Using an example of Group 1 element, describe an experiment to prove above statement.

Your description should include the following :

List of material and apparatus

Procedures of the experiment

Observation

Chemical equation [10 marks]

Group 1 elements react with water to produce alkaline solution.

Z

X

Y

Chemistry Perfect Score/X A-Plus Module 2012 26

14 Table 14 shows the melting point, boiling point and electrical conductivity of compound PQ2

and compound XY.

Compound

Melting point and Boiling point

Electrical conductivity

Solid Molten

P Low No No

Q High No Yes

Table 14

(a) Suggest one possible compound for P.

State the type of compound for P.

Explain why P has low melting and boiling points.

[4 marks]

(b) Chemical formula of compound P is XY.

Suggest one possible electron arrangement of atom X and atom Y.

State the type of chemical bond and explain how the bond is formed between atom X and

atom Y.

[7 marks]

(c) Plan one laboratory experiment to investigate the electrical conductivity of compound Q.

Your answer should include the following :

A list of material and apparatus

Procedure of the experiment

Observation of the experiment

A labeled diagram showing the apparatus set-up [9 marks]

15 (a) Metal P has the following characteristics:-

Based on the information above, state the method used to determine the empirical formula of oxide of

metal P.

Give a reason for your answer.

[2 marks]

(b) Diagram 15 shows the set up of apparatus for an experiment to determine the empirical

formula of the oxide of metal Y.

Diagram 15

The results are obtained as follows:

Table 15

Grey in colour

Can react with steam

Reactive metal

Dry hydrogen

Oxide of metal Y

Combustion tube

Mass of combustion tube + Porcelain dish = 54.30 g

Mass of combustion tube + Porcelain dish + Oxide of Metal Y = 56.69 g

Mass of combustion tube + Porcelain dish + Metal Y = 56.37 g

Chemistry Perfect Score/X A-Plus Module 2012 27

(i) Based on the above information, determine the empirical formula of oxide of metal Y

Given that the relative atomic mass of O = 16, Y = 207

[4 marks]

(ii) Describe the steps that should be taken to ensure that all the air in the combustion

tube has been expelled

.

[3 marks]

(b) Describe an experiment on how to determine the empirical formula of magnesium oxide. In your

description, state the precautions should be taken during the experiment and show how the empirical

formula of magnesium oxide is obtained.

[Relative atomic mass: O = 16; Mg = 24]

[11 marks]

16. (a) The following is the chemical formula of a compound.

SO3

Name the compound and describe the composition of this compound.

[3 marks]

(b) Excess calcium carbonate chips is added to 30 cm3 of 0.5 mol dm

-3 acid HX.

The chemical equation below shows the reaction between calcium carbonate and

acid HX.

CaCO3 + nHX CaX2 + CO2 + H2O

Given that the relative atomic mass of C = 12, O = 16 , Ca = 40 and the molar

volume of any gas is 24 dm3 mol

-1 at room temperature and pressure.

(i) Suggest acid HX and name salt CaX2

Determine the value of n

[3 marks]

(ii) Calculate the maximum volume of carbon dioxide gas produced.

[4 marks]

(c) You are provided with a sample of M oxide powder. The colour of the M oxide powder is green while

the colour of metal M is grey. When it is heated with hydrogen, the M oxide is reduced to M metal.

Based on the information given, describe an experiment to determine the empirical formula of the M

oxide. In your description, include the precautions that should be taken and show how the empirical

formula of M oxide is obtained.

[Relative atomic mass of O = 16 and M = 56]

[10 marks]

Chemistry Perfect Score/X A-Plus Module 2012 28

CHEMISTRY MODULE

SET

1. Electrochemistry

2. Oxidation and Reduction

Chemistry Perfect Score/X A-Plus Module 2012 29

SECTION A

1 Diagram 1 shows the set-up of apparatus of a voltaic cell.

Diagram 1

Based on Diagram 1 , answer the following questions.

(a) What is the energy change that occurs in the voltaic cell?

..................................................................................................................................

[1 mark]

(b) Write the formula of all ions in copper(II) sulphate solution.

..................................................................................................................................

[1 mark]

(i) State the name of the negative terminal of the voltaic cell.

……...............................................................................................................................

[1 mark]

(ii) Give a reason for your answer in (c)(i).

.....................................................................................................................

[1 mark]

(d) (i) State one observation at copper plate.

.....................................................................................................................

[1 mark]

(ii) Write the half equation for the reaction occur at the copper plate.

.....................................................................................................................

[1 mark]

(e) What is the colour change of the copper(II) sulphate solution? Give a reason.

..................................................................................................................................

..................................................................................................................................

[2 marks]

(f) Another experiment is carried out by replacing the zinc plate with P , Q and R metals.

Table 1 shows the results.

.Pair of metal Voltage/V Negative terminal

P/Cu 2.7 P

Q/Cu 2.0 Q

R/Cu 0.5 R

Table 1

Copper(II) nitrate solution

Copper plate Zinc plate

V

Chemistry Perfect Score/X A-Plus Module 2012 30

(i) Arrange P, Q, R and Cu metal in accending order of electropositivity.

..................................................................................................................................

[1 mark]

(ii) Predict the voltage for pair of Q/R.

..................................................................................................................................

[1 mark]

2. Diagram 2 shows the set-up of apparatus to investigate the reaction occurred in test tubes X and Y.

(a) Based on test tube X,

(i) Name the reaction occurred.

…………………………………………………………………………………

[1 mark]

(ii) Write the ionic equation for the reaction.

…………………………………………………………………………………

[2 marks]

(iii) Describe a chemical test to verify the product formed.

........................................................................................................

..........................................................................................................

[2 marks]

(b) Based on test tube Y,

(i) State the observation involved.

................................................................................................................

[1 mark]

(ii) Experiment is repeated by using copper to replace zinc.

State the observation involved.

..................................................................................................................

[1 mark]

(c) Compare the answer in (b) (i) and (b) (ii) and explain why there is a difference in the observation.

............................................................................................................................. ................

.............................................................................................................................................

[2 marks]

(d) When iron is exposed to water and oxygen, it rusts easily. State one method to prevent the rusting of

iron.

............................................................................................................................. .............

[1 mark]

Test tube X Test tube Y

Agar solution + Potassium

hexacyanoferrate(III) solution

+ Phenolphthalein

Iron nail coiled with zinc

Diagram 2

Zinc

Iron(III) sulphate solution

Heat

Chemistry Perfect Score/X A-Plus Module 2012 31

SECTION B

3 Diagram 3.1 shows the set-up of apparatus to investigate the electrolysis of magnesium chloride

1.0 mol dm-3

solution.

Diagram 3.1

(a) (i) Based on Diagram 3.1;

State the name of the products at the cathode and the anode.

Explain the reaction at cathode and anode. Include the following in your explanation:

List the ions attracted to cathode and anode.

State the ions selectively discharged at cathode and anode.

The reason why the ions are selectively discharged.

Half equation for the reaction at cathode and anode.

[10 marks]

(ii) Predict the product at anode and cathode if magnesium chloride 1.0 mol dm-3

solution

is replaced by magnesium chloride 0.0001 mol dm-3

solution.

[2 marks]

(b) Diagram 3.2 shows the set up of apparatus when cell X is combined with cell Y.

Compare and contrast cell X and cell Y in terms of following:

Types of cells

Energy changes

Name of electrodes

Ions in the electrolyte

Half equations

Observations

. [8 marks]

Copper plate

Copper(II) sulphate

solution

Magnesium

plate

Cell X Cell Y

Copper plate

Diagram 3.2

V

Magnesium chloride 1.0 mol dm-3

A

Carbon

electrodes

Chemistry Perfect Score/X A-Plus Module 2012 32

4 (a) The following are the formulae of two compounds.

Na2O PbO2

(i) Based on the two formulae , state the oxidation number for sodium and lead.

[ 2 marks]

(ii) State the name of the compounds based on the IUPAC nomenclature.

[ 2 marks]

(b) Diagram 4 shows the observation of two experiment to study the effect of metal P and metal Q on the

rusting of iron.

Experiment Observation

Experiment 1

Large amount of dark blue precipitate

Experiment 2

No dark blue precipitate.

Solution turns pink.

Diagram 4

(i) Suggest metal P and metal Q.

(ii) Explain the observations and write the chemical equation for the reaction in the experiment 1

and experiment 2.

[ 10 marks]

(c) The equation shows a redox reaction. M is a metal.

X(s) + CuSO4 (aq) XSO4 (aq) + Cu(s)

Suggest metal X and explain the redox reaction in terms of the transfer of electrons .

[6 marks]

SECTION C

5 Diagram 5 shows the set-up of apparatus for electrolysis of 1.0 mol dm-3

sodium sulphate solution.

Diagram 5

(a) State the name of gas produced at electrode X and electrode Y.

[2 marks]

Carbon electrode Y Carbon electrode X

1.0 moldm-3

sodium

sulphate solution

Chemistry Perfect Score/X A-Plus Module 2012 33

(b) Explain the reaction at electrode X and electrode Y. Include the following inyour explanation.

List of ion attracted to each electrodes, X and Y.

State the name of the ions selectively discharged at each electrode.

The reason why the ion are selectively discharged.

[5 marks]

(c) When sodium sulphate solution is replaced by a solution of substance Z with same concentration, the

equal gas produced at electrode X and electrode Y .

Suggest the substance Z. Write the half equation for the reaction at electrode X.

[3 marks]

(d) Zinc is placed above metal A in the electrochemical series. Zinc and metal A can be used to build a

chemical cell, using suitable apparatus and the following chemicals ;

Zinc

Zinc nitrate solution

Metal A

A nitrate solution

By naming metal A and A nitrate solution, describe how you build the chemical cell.

Include a labelled diagram in your answer.

On your diagram, mark the direction of electron flow, the positive terminal and the negative

terminal.

[ 10 marks]

6 (a) The following are the equations of two reactions:

Determine which reaction is a redox reaction.

Explain your answer in terms of oxidation number.

[4 marks]

(b) Table 6 shows the observations of two experiments to determine the position of carbon in the

reactivity series of metal.

Experiment Reactants Observation

I Carbon + oxide of metal P A flame spreads to the whole mixture.

A brown residue is formed.

II Carbon + oxide of metal Q No change

III Carbon + oxide of metal R A glow spreads to the whole mixture. A

grey residue is formed.

Based on observations in Table 6, arrange the reactivity of metals P, Q, and R in descending order.

Explain your answer.

[6 marks]

(c)

By using a named metal as a reducing agent and a named halogen as an oxidising agent, describe

briefly how you would carry out these two conversion.

Describe a test to show that each conversion has taken place.

[ 10 marks]

Reaction I : NaOH + HCl NaCl + H2O

Reaction II : Mg + Zn(NO3)2 Mg(NO3)2 + Zn

Table 6

Iron(II) ions can be converted to iron(III) ions and iron(III) ions can be converted back to iron(II) ions.

Chemistry Perfect Score/X A-Plus Module 2012 34

CHEMISTRY MODULE

SET

1. Acids and Bases 2. Salts 3. Rate of reaction

4. Thermochemistry

Chemistry Perfect Score/X A-Plus Module 2012 35

SECTION A

1. Diagram 1 shows four test tubes labeled A,B,C and D which are used to study the relationship

between pH value of acid and alkali with the molarity.

pH paper

A B C D

5 cm3HCl 5 cm

3HCl 5 cm

3 NaOH 5 cm

3 NaOH

0.1 mol dm-3

0.01 mol dm-3

0.1 mol dm-3

0.01 moldm-3

(a) Determine which solution has

(i) highest pH value.

` …………….……………………………………………………………………………........

[1 mark]

(ii) lowest pH value. Give a reason for your answer.

……………………………………………………………………………………….............

[2 marks]

(b) If the hydrochloric acid in test tube B is replaced with 5 cm3 of 0 .01 mol dm

-3ethanoic acid,

predict the pH value of the solution. Explain your answer

…………………………………………………………………………………………………...………..

…………………………………………………………………………………………………

…………………………………………………………………………………………….

[3 marks]

(c) Excess of magnesium powder is added to 5 cm3 of 0.1moldm

-3 hydrochloric acid in test tube A

(i) State the name of the products formed.

.

……...………………………………………………………………………………………..

[1 mark]

(ii) Write the chemical equation for the reaction in test tube A

………………………………………………………………………………………………

[1 mark]

(iii) Calculate volume of hydrogen gas released at room conditions in test tube A

[1 mol of gas occupies 24 dm3 at room conditions]

[3 marks]

Diagram 1

Chemistry Perfect Score/X A-Plus Module 2012 36

Add water

(d) If the solution in test tube C is added to lead(II) nitrate solution. State the observation from the

reaction.

…….…………………………………………………………………………………………

[1 mark]

2. (a) Diagram 2.1 shows the pH value of glacial ethanoic acid in solvent P and solvent Q

respectively.

(i) Suggest solvent P and solvent Q.

Solvent P: ……………………………………………………….………...………………

Solvent Q: ……………………………………………………………………………….

[2 marks]

(ii) If magnesium ribbon is added into beaker containing glacial ethanoic acid and solvent

P, what can be observed?

……………………………………….…………………………………………………

[1 mark]

(iii) Explain why ethanoic acid in solvent P and solvent Q has different the pH value.

….………………………………………………………………………………………

….………………………………………………………………………………………

….………………………………………………………………………………………

...………………………………………………………………………………………

[3 marks]

(b) Diagram 2.2 shows the concentration of hydrochloric acid in volumetric flask when a certain

volume of hydrochloric from the beaker is transferred to the volumetric flask and added with

water

7.0 4.8

Glacial ethanoic acid

+ solvent P Glacial ethanoic acid +

solvent Q

100 cm3 of 0.5 moldm

-3 hydrochloric acid

Diagram 2.1

Diagram 2.2 250 cm

3 of 0.04 moldm

-3 hydrochloric acid

Chemistry Perfect Score/X A-Plus Module 2012 37

(i) What happen to the pH value of the hydrochloric acid when water is added to the acid?

Give a reason for your answer.

….……………………………………………………………………………………………

.………………………………………………………………………………………………

[2 marks]

(ii) Calculate the volume of hydrochloric acid that is needed to prepare 250cm3 of 0.04 mol dm

-3

hydrochloric acid.

[2 marks]

3. A student carried out an experiment to investigate the properties of three solutions. Diagram 3 shows the

results of the experiments.

Test tube P Q R Set-up of

apparatus

Observation

The red litmus

paper turned blue. No change

Diagram 3

(a) What is meant by strong alkali?

............................................................................................................................. ..........

[1 mark]

(b) What is the property of the solution in test tube P?

.......................................................................................................................................

[1 mark]

(c) What are the types of particles that exist in the test tubes P and Q?

Particles in the test tube P: ..........................................................................................

Particles in the test tube Q: .........................................................................................

[2 marks]

(d) Is there any changes of colour of the litmus paper in test tube Q? Give a reason to your answer.

............................................................................................................................. .........

......................................................................................................................................

[2 marks]

Ammonia gas

dissolved in

water

Red litmus

Paper

Ammonia gas

dissolved in

propanone

Red litmus

Paper

Hydrogen

chloride gas

dissolved in water

Magnesium

Chemistry Perfect Score/X A-Plus Module 2012 38

(e) (i) What can be observed in test tube R?

............................................................................................................................. .........

[1 mark]

(ii) Write a chemical equation for the reaction in test tube R.

.......................................................................................................................................

[2 marks]

(iii) 2.4 g of magnesium is reacted completely with the solution in test tube R.

Calculate the volume of the hydrogen gas produced at room condition

[Relative atomic mass: Mg,24; 1 mol of gas occupies 24 dm3 at room conditions]

[2 marks]

4 Diagram 4 shows the apparatus set-upfor the neutralisation reaction between sulphuric acid and

potassium hydroxide solution for preparation of salt X.

Diagram 4

(a) (i) State the colour change of the solution in the conical flask at the end point.

………………………………………………………………………………….…………………

[1 mark]

(ii) Write a chemical equation for the above reaction.

…………………………………………………………………………………………………….

[2 marks]

(iii) Calculate the concentration of potassium hydroxide used.

[2 marks]

(b) (i) State the name of salt X.

……………………………………………………………………………………………..

25.0 cm3

potassium hydroxide

solution + phenolphthalein

indicator

15 cm3of 0.1mol dm

-3

sulphuric acid

Chemistry Perfect Score/X A-Plus Module 2012 39

[1 marks]

(ii) Calculate the maximum mass of salt X formed.

[Molar mass of salt X = 174 g mol-1

]

[3 marks]

(c) (i) The experiment is repeated with 0.1 mol dm-3

nitric acid to replace sulphuric acid. Predict the

volume of nitric acid needed to neutralize completely potassium hydroxide

………………………………………………………………………………………………..

[1 mark]

(iii) Explain your answer in (c) (i).

......................................................................................................................................................

............................................................................................................................. .........................

[2marks]

5. Diagram 5 shows a series reaction of copper compound.

(a) Copper(II) nitrate solution reacts with sodium carbonate solution to form copper(II) carbonate

precipitate.

(i) What is the colour of copper(II) carbonate?

……………………………………………………………………………………….............

[1 mark]

(ii) State the name of the reaction.

............................................................................................................................. ............................

[1 mark]

(b) Heating of copper(II) carbonate produces copper(II) oxide and gas X.

(i) State the name of gas X.

………………………………………………………………………………………………..

[1 mark]

(ii) Write the chemical equation of the reaction.

.............................................………………………………………………………......................

[2 mark]

Copper(II)

carbonate

Copper(II)

oxide

Sodium carbonate Copper(II)

nitrate

Copper(II) sulphate

Diagram 5

Acid Y

Heat Gas X +

Chemistry Perfect Score/X A-Plus Module 2012 40

(iv) Draw a labeled diagram for the heating of copper(II) carbonate to produce copper(II) oxide

and gas X. In your diagram show how gas X is tested.

[2 marks]

(c) Copper(II) carbonate reacts with acid Y to produce copper(II) sulphate. The chemical equation is

shown below.

CuCO3 + Acid Y → CuSO4 + CO2 + H2O

(i) What is acid Y?

…………………………………………………………………………………………………

[1 mark]

(ii) 12.4 g copper(II) carbonate reacts completely with excess acid Y.

Calculate the mass of copper(II) sulphate formed.

[Relative atomic mass: C = 12, O=16 , S = 32, Cu = 64]

[3 marks]

6. Three experiments were conducted to investigate factors affecting the rate of reaction. The results are

shown in the Table 6

Experiment Reactants Temperature / 0C

Time taken for all the

magnesium to dissolve/s

I 0.4g magnesium ribbon and 50 cm

3

1 moldm-3

hydrochloric acid 30 100

II 0.4g magnesium powder and 50 cm

3

1 moldm-3

hydrochloric acid 30 60

III

0.4g magnesium ribbon and 50 cm3

1 moldm-3

hydrochloric acid and copper(II)

sulphate solution

30 45

Table 6

(a) Write a chemical equation to show the reaction between magnesium and hydrochloric acid.

………………………………………………………………………………………………

[2 marks]

(b) Calculate the number of mole of

(i) Magnesium

[Relative atomic mass of Mg = 24]

[1 mark]

(ii) Hydrochloric acid

[1 mark]

Chemistry Perfect Score/X A-Plus Module 2012 41

(c) If hydrochloric acid used is excess, calculate the maximum volume of hydrogen gas produce at

room temperature and pressure.

[1 mole of gas occupies the volume of 24 dm3 at room temperature and pressure]

[2 marks]

(d) Calculate the average rate of reaction for

(i) Experiment I

[1 mark]

(ii) Experiment II.

[1 mark]

(iii) What is the purpose of using copper(II) sulphate?

…….………………………………………………………………………………………

[1 mark]

(f) The factor that affects the rate of reaction in this experiment is total surface area and the use of

catalyst. State two other factors that affect the rate reaction in this experiment.

………………………………………………………………………………………………

……..………………………………………………………………………………………

[2 marks]

7. Diagram 7 shows two experiments to investigate one of the factors that affect the rate of reaction between

zinc and hydrochloric acid

Diagram 7

(a) (i) Based on Diagram 7, state the factor that affect the rate of reaction in this experiment.

………………………………………………………………………………………………….

[1 mark]

50 cm3 1 mol dm-3HCl

Hydrogen gas

Excess zinc

granules

Experiment I

50 cm3 1 mol dm-3HCl + copper(II) sulphate

solution

Hydrogen gas

Excess zinc

granules

Experiment II

Chemistry Perfect Score/X A-Plus Module 2012 42

(ii) Besides measuring the change of volume of gas released at certain time interval, suggest another

measurable change to determine the rate of reaction?

…………………………………………………………………………………………………..

[1 mark]

(b) In Experiment II, 2.0 cm3 0.5 moldm

-3copper(II) sulphate solution is added. The maximum volume of

hydrogen gas released in Experiment I is V cm3.

(i) Compare the volume of gas released in Experiment I and Experiment II.

Give a reason for your answer.

…………………………………………………………………………………………………..

………………………………………………………………………………………………….

[2 marks]

(ii) The graph of volume of hydrogen gas released against time in Experiment I is shown below.

Sketch the curve for Experiment II on the same axes in the graph above.

[2 marks]

(iii) With reference to collision theory, explain how copper(II) sulphate solution affect the rate of

reaction in this experiment.

[3 marks]

(c) Table 7.1 shows three experiments done by a student.

Experiment Reactants

A Excess calcium carbonate chips + 25 cm

3 1.0 mol dm

-3

hydrochloric acid

B Excess calcium carbonate chips + 25 cm

3 0.5 mol dm

-3

hydrochloric acid

C Excess calcium carbonate chips + 100 cm

3 0.5 mol dm

-3

hydrochloric acid

Table 7.1

Time / s

Volume of gas

released/ cm3 Key : Experiment I :

Experiment II : …

…..

Chemistry Perfect Score/X A-Plus Module 2012 43

The graph of volume of carbon dioxide released against time is sketched as shown in graph 7

Based on the above table and graph, determine which curve represents the results for experiment B

and C. Write your answers in the boxes provided.

[1 mark]

8. An experiment is conducted to study the heat of displacement for reaction between copper(II) sulphate

and excess magnesium powder. 50.0 cm3 of 0.5 mol dm

-3 copper(II) sulphate solution is poured into a

polystyrene cup and the initial temperature is recorded. The excess magnesium powder is added to the

same polystyrene cup. The mixture is stirred slowly and the highest temperature is recorded.

Initial temperature of copper(II) sulphate solution = 28.5 oC

Highest temperature of mixture = 33.5 oC

[Relative atomic mass : Cu=64; S=32; O=16; Zn= 65;

(a) What is the meaning of heat of displacement in this experiment?

............................................................................................................................

............................................................................................................................ [1 mark]

(b) Why does zinc in the form of powder is used in this experiment?

………………………………………………………………………………………… [1 mark]

(c) Write the ionic equation for the reaction in this experiment.

............................................................................................................................

[2 marks]

(d) (i) Based on the experiment, calculate the heat energy released.

[1 mark]

(ii) number of mole of copper(II) sulphate that has reacted

[1 mark]

(iii) heat of displacement in this reaction

[2 marks]

(e) Draw an energy level diagram for the reaction.

[3 marks]

Time/s

Volume of

carbon

dioxide

/cm3 Experiment

A

Graph 7

Chemistry Perfect Score/X A-Plus Module 2012 44

5 g of zinc powder

50 cm3 of 0.2 mol dm

-3

copper(II) sulphate solution

Plastic cup

(f) Why polystyrene cup is used in this experiment?

…………………………………………………………………………………………………………

[1 mark]

9. Diagram 9 shows the apparatus set-up to determine heat of displacement of copper by using zinc

powder. The result of the experiment is recorded in the Table 9.

Diagram 9

Initial temperature of copper(II) sulphate solution (oC) 30.0

Highest temperature of the mixture (oC) 38.0

Table 9

(a) What is the meaning of heat of displacement?

………………………………………………………………………………………

………………………………………………………………………………………

[1 mark]

(b)

(c)

Why plastic cup is used in this experiment.

……………………………………………………………………………………… [1 mark]

State the type of reaction that occurs based on the temperature change.

………………………………………………………………………………………

[1 mark]

(d) Calculate :

(i) the heat change for the reaction

[Specific heat capacity of solution = 4.2 J g-1

oC

-1; Density of solution = 1 g cm

-3]

[1 mark]

(ii) the heat of displacement for the reaction.

[2 marks]

(e) Draw energy level diagram for the reaction.

[3 marks]

Chemistry Perfect Score/X A-Plus Module 2012 45

(f) Experiment is repeated by using 100 cm3 of 0.2 mol dm

-3 of copper(II) sulphate solution.

(i) Predict the temperature change in the experiment.

.

……………………………………………………………………………………...

[1 mark]

(ii) Explain your answer in (e) (i).

……………………………………………………………………………………...

……………………………………………………………………………………...

……………………………………………………………………………………...

[2 marks]

10. The equation for combustion of propanol in excess oxygen is given below.

(a) What is meant by heat of combustion in this reaction?

..........................................………………………………………………………………………

[1 mark]

(b) State two information that can be obtained from the equation

...........................................……………………………………………………………………

………………………………………………………………………………………………

[2 mark]

(c) Heat given out from the complete combustion of 1.2 g propanol is used to heat 200 cm3 of water.

Calculate:

(i) The heat energy given out in the reaction.

[Molar mass of propanol, C3H7OH = 60 gmol-1

]

[2 marks]

(ii) The temperature change in the reaction.

[Spesific heat capacity of water = 4.2 Jg-1 o

C-1

; Density of water = 1 gcm-3

]

[2 marks]

(d) Draw the energy level diagram for this reaction.

[3 marks]

C3H7OH + 9 O2 3CO2 + 4H2O , ∆H = -2015 kJ mol-1

2

2

Chemistry Perfect Score/X A-Plus Module 2012 46

(e) The value of the heat of combustion of propanol obtained from the experiment is less than the

theoretical value. Suggest one precaution step that should be taken in order to get a more accurate result.

............................................................................................................................................................

[1 mark]

(f) Table 10 show s the molecular formula and the heat of combustion for methanol and ethanol.

Alcohol Molecular formula Heat of combustion/kJmol-1

Methanol CH3OH -728

Ethanol C2H5OH -1376

Based on the information in Table 10, explain why there is a difference in the value of heat of

combustion between methanol and ethanol.

............................................................................................................................. .............

..........................................................................................................................................

............................................................................................................................. .............

..........................................................................................................................................

[3 marks]

SECTION B

11. (a) A student has carried out an experiment to construct an ionic equation for the formation of lead(II)

iodide. Seven test tubes of the same size were labeled 1 to 7. A fixed volume of 5.0 cm3 of 1.0 mol

dm-3

potassium iodide solution was poured in each test tube. The volume of 1.0 mol dm-3

lead(II)

nitrate solution that added are shown in Table 11. The height of precipitate formed in each test tube

was measured. The results are shown in Table 11.

Table 11

(i) Based on Table 11, plot a graph of the height of precipitate against volume of lead(II) nitrate

solution.

[3 marks]

(ii) Determine the number of moles of lead(II) ions and iodide ions that are required for the

formation of lead(II) iodide. Your answer should consist of the following:

the volume of lead(II) nitrate solution that had reacted completely with 5.0 cm3 of 1.0

mol dm-3

potassium iodide

calcúlate the number of moles of lead(II) ions and iodide ions

calculate the number of moles of iodide ions that has reacted with 1 mol of lead(II) ions.

write the ionic equation for the formation of lead(II) iodide.

[7 marks]

Test tube 1 2 3 4 5 6 7

Volume of 1.0 moldm-3

lead(II)

nitrate solution / cm3

0.5 1.0 1.5 2.0 2.5 3.0 3.5

Height of precipitate /cm 1.1 2.2 3.4 4.4 5.5 5.5 5.5

Table 10

Chemistry Perfect Score/X A-Plus Module 2012 47

(b) Diagram 11 shows the flow chart of reaction of salt J. X oxide which is brown when hot and yellow

when cold is formed when salt J is heated strongly. Salt J dissolves in water to form colourless

solution. The solution formed is tested with potassium iodide, KI solution.

+ +

H2O

Diagram 11

Based on the information in Diagram 11:

(i) Identify salt J, X oxide, brown gas Y, colourless gas Z and yellow precipitate L.

[5 marks]

(ii) State the name of the anion present in salt J. Then describe one chemical test to determine the

presence of anion in salt J.

[5 marks]

12. Diagram 12.1 shows a series of reaction for salt S which is a green colour compound. Salt S is heated

strongly to produce black residue of compound T and gas U.

Compound T reacts with sulphuric acid to form blue solution of compound W.

Diagram 12.1

Based on Diargram 12.1:

(a) (i) Suggest one formula of the anion in salt S.

[1 mark]

(ii) Identify salt S, compound T, gas U and compound W.

[4 marks]

(b) Write a chemical equation for the reaction between compound T and sulphuric acid.

[2 marks]

(c) Compound W is a soluble salt. Describe chemical test to verify the cation and anion in compound W.

[5 marks]

Salt J X Oxide Brown gas Y Colourless gas Z

Salt J solution Yellow precipitate L

Potassium iodide

solution

Heat + Salt S Compound T Gas U

Compound W

+ H2SO4

Lime water turns cloudy

Pass through

lime water

Chemistry Perfect Score/X A-Plus Module 2012 48

(d) Diagram 12.2 shows the chemical equation for the reaction between blue solution of compound W and

barium nitrate solution.

Diagram 12.2

Based on Diagram 12.2:

(i) State the name of salt X and salt Y.

[2 marks]

(ii) State one observation and name the type of reaction occurred.

[2 marks]

(iii) Compound W reacts with 50 cm3 of 0.1 mol dm

-3 barium nitrate solution.

Write the ionic equation for the reaction and calculate the mass of salt X produced.

[Relative molecular mass of salt X: 233]

[4 marks]

13 (a) Table 13 shows the incomplete observation for two experiments to construct balanced chemical

equation.

Experiment Procedure Observation

A Copper(II) carbonate is heated and the gas

produced is passed through lime water..

Green solid turns black.

The lime water turns milky.

B Potassium iodide solution is added to lead(II)

nitrate solution.

Table 13

(i) Based on the observation, state the name of the products in experiment A and write the chemical

equation for the reaction.

[3 marks ]

(ii) State one observation in experiment B and state the name of the products formed.

Write the chemical equation for the reaction.

[4 marks ]

(b) You are given aluminium nitrate solution and zinc nitrate solution.

Describe chemical tests that can be used to verify the cations and anion in each solutions.

[8 marks]

(c) Excess of solid copper(II) oxide is added to 25 cm3 of 1.0 mol dm

-3sulphuric acid to form copper(II)

sulphate.

[Relative atomic mass, Cu=64, S=32, O=16]

(i) Write the chemical equation for the reaction

(ii) Calculate the mass of copper (II) sulphate produced

[5 marks]

Compound W(aq)+ Ba(NO3)2(aq) → Salt X(s) + Salt Y(aq)

Chemistry Perfect Score/X A-Plus Module 2012 49

14 (a) (i) Rate of a given reaction is important in industries and in our everyday lives.

State the four factors that affect the rate of reaction. [4 marks]

(ii) What are the conditions required for the production of ammonia in Haber Process? [3 marks]

(b) A student carried out two experiments to investigate the effect of concentration on the rate of reaction.

Diagram 3.1 shows the set-up of apparatus of the experiments.

Experiment

Set-up of apparatus

I

Diagram 14.1

Table 14.2 shows the result of the experiments.

Time /s 0 30 60 90 120 150 180 210

Volume of gas of Experiment I /cm3

0.00 5.00 10.00 14.20 18.00 21.30 24.00 26.00

Volume of gas of Experiment II /cm3

0.00 10.00 17.00 23.00 25.00 26.00 26.00 26.00

Table 14.2

(i) Plot the graph of the volume of carbon dioxide gas against time for Experiment I and II on

the same axes on the graph paper provided .

[4 marks]

(ii) Calculate the average rate of reaction for Experiment I and II.

[4 marks]

(iii) Compare the rate of reaction between Experiment I and Experiment II.

Explain the differences in the rate of reaction with reference to the collision theory.

[5 marks]

0.2 g calcium carbonate

powder

Excess hydrochloric acid

0.2mol dm-3

Water

Air

0.2 g calcium carbonate

powder

Excess hydrochloric acid

0.5mol dm-3

Water

Air

II

Chemistry Perfect Score/X A-Plus Module 2012 50

Question 14 (b) (i)

Chemistry Perfect Score/X A-Plus Module 2012 51

15. (a) A fixed mass of magnesium is added to 50 cm3 0.5 mol dm

-3 of excess sulphuric acid . State 3 ways to

shorten the time for the magnesium to dissolve completely.

[3 marks]

(b) When potassium chlorate(V) is heated, it decomposed to release oxygen gas according to the equation

below.

2KClO3 2 KCl + 3O2

(i) Name a suitable catalyst that can be used to increase the rate of decomposition of potassium

chlorate(V)

[1 mark]

(ii) State 2 characteristics of a catalyst

[2 marks]

(iii) Contact Process is an industrial process to manufacture sulphuric acid in large scale. State and

justify any two of the conditions involved in this process .

[4 marks]

(c) The graph below shows the change of rate of reaction with time when excess calcium carbonate

granules is reacted with dilute hydrochloric acid. State and explain how the rate of reaction changes

with time.

[3 marks]

(d) Describe an experiment to study the effect of catalyst manganese(IV) oxide on the rate of

decomposition of hydrogen peroxide.

[7 marks]

16.(a) Diagram 16.1 and 16.2 show energy level diagrams.

(i) Compare both the energy level diagrams above. Your explanation should include the

following

ionic equations

type of chemical reactions

energy content of reactants and products [6 marks]

(ii) Based on diagram 16.1, calculate the change in temperature of the solution if excess

magnesium powder is added to 50 cm3 of 0.2 mol dm

-3 iron(II) sulphate solution.

[Given that Specific heat capacity of solution : 4.2 J g -1 o

C-1

]

[3 marks]

(b) Explain why the heat of reaction between 1.0 mole of silver nitrate solution and 1.0 mole of sodium

chloride solution is the same as the heat of reaction between 1.0 mole of silver nitrate solution and

0.5 mole of magnesium chloride solution. [4 marks]

Diagram 16.1 Diagram 16.2

Time / s

Rate of reaction

MgSO4 + Fe

Mg(s) + FeSO4

Energy

ΔH= - 200 kJmol-1

Energy

CaCl2 + Na2CO3

CaCO3 + 2NaCl

ΔH= + 12.6 kJmol-1

Chemistry Perfect Score/X A-Plus Module 2012 52

(c) A student carried out an experiment to determine the heat of neutralisation for the reaction between

50 cm3 of 2.0 mol dm

-3 hydrochloric acid and 100 cm

3 of 2.0 mol dm

-3 sodium hydroxide solution.

The following data was obtained:

Initial temperature of hydrochloric acid = 30.2 oC

Initial temperature of sodium hydroxide solution = 30.2 oC

Highest temperature of the mixture of the solutions = 42.2 oC

(i) Calculate the heat of neutralisation for this reaction.

[Given that specific heat capacity of solution = 4.2 J g -1 o

C -1

]

[3 marks]

(ii) If the experiment is repeated using 100 cm3 of 2.0 mol dm

-3 hydrochloric acid and 100 cm

3

of 2.0 mol dm-3

sodium hydroxide solution and all other conditions are the same, predict the

increase in temperature. Explain your answer.

[4 marks]

SECTION C

17. (a) Acid HX is a monoprotic acid while H2X is a diprotic acid. Both acid HX and H2X are strong acid.

Using suitable examples, explain what is meant by

(i) diprotic acid

(ii) strong acid

[ 4 marks ]

(b) Table 9 shows the pH value of sodium hydroxide and aqueous ammonia of the same concentration

Explain why sodium hydroxide solution and aqueous ammonia of the same concentration have different

pH value.

[ 6 marks ]

(c) Describe how to prepare 250 cm3 of 1.0 mol dm

-3 potassium hydroxide starting from solid potassium

hydroxide. State the size of volumetric flask used and calculate mass of potassium hydroxide needed.

[Relative atomic mass: H, 1; O, 16; K, 39]

[ 10 marks ]

18 (a) Salts is widely used in various fields.

Name one example of salt and its uses in each of the following fields:

(i) agriculture

(ii) food preparation

(iii) medicine

[6 marks]

(b) By using all the chemical substances given bellow and suitable apparatus, describe a laboratory

experiment to prepare dry zinc sulphate salt.

In your description, include chemical equations involved.

[12marks]

Alkali Concentration / moldm-3

pH

Sodium hydroxide solutiom 0.1 13

Ammonia aqueous solutiom 0.1 11

zinc nitrate solution

Dilute sulphuric acid

sodium carbonate solution

Chemistry Perfect Score/X A-Plus Module 2012 53

19

(a) Write an ionic equation to represent the reaction given in the box above.

[2 marks]

(b) The rate of the above reaction can be measured based on the mass of sulphur produced.

Based on this statement,state the meaning of the rate of reaction.

[2 marks]

(c) Suggest two factors that can affect the rate of reaction stated above and state the respective effects on

the rate of reaction.

[4 marks]

(d) You are given a conical flask, a piece of white paper and all other common apparatus found in normal

school laboratory. Describe an experiment to show the effect of one of the factors that you have given

in (b). In your answer, you are required to show how the data obtained can be analysed to help you

draw the conclusion for your experiment.

[12 marks]

20. Table 20.1 shows the data from Experiment I and Experiment II that were carried out to study the rate

of reaction of magnesium ribbon with two acids, X and Y .

Experiment Reactants Products

I Excess of magnesium ribbon and 50

cm3 of acid X 1.0 mol dm

-3

Magnesium chloride and hydrogen gas

II Excess of magnesium ribbon and 50

cm3 of acid Y 1.0 mol dm

-3

Magnesium sulphate and hydrogen gas

Table 20.1

(a) (i) State the name of acids X and Y.

Write the chemical equation for the reaction of acid X with magnesium.

[3 marks]

(ii) Calculate the number of mol of acid X or acid Y that react with excess magnesium ribbon.

[1 mark]

(iii) Based on this experiment what is meant by the rate of reaction?

[1 mark]

(b) (i) At the same axis, sketch the graph of volume of gas against time for experiment I and

experiment II.

[2 marks]

(ii) Compare the rate of reaction in experiment I and II . Explain your answer based on collision

theory.

[5 marks]

(c) Describe one laboratory experiment to conduct the Experiment I or Experiment II to determine

the rate of reaction. Your answer should include the following :

- A labeled diagram showing the apparatus set-up

- Procedures of the experiment

- A table to collect the data

[8 marks]

Sodium thiosulphate solution reacts with hydrochloric acid to form sulphur,

pungent gas sulphur dioxide, water and salt

Chemistry Perfect Score/X A-Plus Module 2012 54

21 (a) A student carried out an experiment in the laboratory to determine the heat of precipitation of

silver chloride, AgCl using the following chemical substances :

Table 21.1 shows the result of the experiment :

Initial temperature of silver nitrate, AgNO3 solution 29.0 oC

Initial temperature of sodium chloride, NaCl solution 29.0 oC

Highest temperature of reaction mixture 33.0 oC

Table 21.1

(i) Calculate the heat of precipitation of silver chloride

[ Specific heat capacity for all solution is 4.2 Jg-1o

C-1

and the density of all solution is 1.0 g

cm-3

]

(ii) Draw an energy level diagram for the reaction between silver nitrate and sodium chloride.

[4 marks]

(b) Table 10.2 shows the heat released for Experiment I, II and III using different acid that has been

reacted with sodium hydroxide solution.

Experiment Chemical Equation Heat released

I HCl + NaOH → NaCl + H2O 57

II CH3COOH + NaOH CH3COONa + H2O 54

III H2SO4 + 2NaOH Na2SO4 + 2H2O 114

Based on Table 21.2, explain the difference in heat released between :

(i) Experiment I and Experiment II

(ii) Experiment I and Experiment III [6 marks]

(c) Describe a laboratory experiment to determine the heat of displacement of metal by a more

electropositive metal. In your description, include the following aspects :

Materials and apparatus needed

Procedure of experiment

A table to collect data

Calculation method

[10 marks]

25 cm3 of 0.5 mol dm

-3 silver nitrate solution

25 cm3 of 0.5 mol dm

-3 sodium chloride solution

Chemistry Perfect Score/X A-Plus Module 2012 55

22 (a) What is meant by exothermic and endothermic reaction?

Compare the changes in energy content of the reactants and products for both of the reactions.

[4 marks]

(b) Diagram represent the energy level diagram for a chemical reaction

State four information that can be obtained from the above diagram.

[4 marks]

(c) Reaction I and II below are the thermochemical equation for the heat of precipitation.

Reaction I : AgNO3 + NaCl → AgCl + NaNO3 H = - 210 kJmol-1

Reaction II : AgNO3 + KCl → AgCl + KNO3 H = - 210 kJmol-1

Explain why the value of heat of precipitation in reactions I and II are the same.

[4 marks]

d)

Describe a laboratory experiment to determine the heat of reaction for the above reaction. In your

answer, include the following :

chemicals required

procedures of the experiment

results and calculation involved

[8 marks]

23. The thermochemical equation for the combustion of butanol is given as follows:

C4H9OH + 6O2 4CO2 + 5H2O ∆H = -2679 kJmol-1

[Relative atomic mass : H=1, C=12, O=16, specific heat capacity of water = 4.2 Jg-1

oC

-1]

(a) State three information that can be obtained from the above equation.

[3 marks]

(b) Calculate the mass of butanol that must be burnt to raise the temperature of 400 cm3 of water

by 25°C.

[3 marks]

(c)

Describe an experiment to determine the heat of combustion of butanol. Your answer should

include:

(i)

apparatus set-up [2 marks]

(ii) procedure of the experiment [6 marks]

(iii) data obtained from the experiment [2 marks]

(iv) calculation of heat of combustion of butanol. [4 marks]

Energy

A + B

C + D

ΔH= + x kJ mol-3

Ca2+

(aq) + CO32-

(aq) → CaCO3 (s) ∆H = + 12.6 kJmol-1

Chemistry Perfect Score/X A-Plus Module 2012 57

SECTION A

1. Diagram 1 shows the structural formula of compound X.

Diagram 1

(a) Compound X is an unsaturated hydrocarbon.

What is the meaning of unsaturated hydrocarbon?

......……........……………………………………......................................................................

[2 marks]

(b) State the homologous series for compound X.

......................……………………………………......................................................................

[1 mark]

(c) Name the compound X.

......................……………………………………......................................................................

[1 mark]

(d) At 180 oC and in the presence of nickel as catalyst, compound X can be changed into saturated

hydrocarbon compound.

(i) Name the reaction.

......................……………………………………......................................................................

[1 mark]

(ii) Draw the structural formula for the compound formed.

[1 mark]

(e) Compound X burns completely in excess oxygen.

(i) Write a balanced chemical equation for the complete combustion of X.

..............................................................................................................................................

[2 marks]

(ii) 2.1 g of compound X undergoes complete combustion at room conditions.

Calculate the volume of carbon dioxide gas released.

[1 mol of gas occupies 24 dm3 at room conditions; Relative atomic mass: H = 1; C = 12]

[2 marks]

Chemistry Perfect Score/X A-Plus Module 2012 58

2. Diagram 2 shows a series of reactions.

Compound P with the molecular formula C2H6O, can be prepared through fermentation of glucose

solution.

Diagram 2

(a) Name the compound P.

......………………………………………………………………………...................................

[1 mark]

(b) State the functional group of compound P.

......………………………………………………………………………...................................

[1 mark]

(c) In the reaction I, compound Q is produced when an acidified potassium dichromate (VI) solution is

added into a test tube containing compound P.

(i) Name the reaction I.

……………………………………………………………………....................................

[1 mark]

(ii) State one observation for this reaction.

...................………………………………………………………………………..............

[1 mark]

(iii) Draw the structural formula of compound Q.

[1 mark]

(d) In the reaction II, compound R is formed when compound P reacts with compound Q in the

presence of concentrated sulphuric acid.

(i) Name the reaction II.

……………………......................………………………………………………..............

[1 mark]

(ii) Name the compound R.

……………………………………………………………………..................................

[1 mark]

(iii) Give one special physical property of compound R.

..……………………………………………………………………..................................

[1 mark]

(iv) Write the chemical equation for the reaction II.

…………………………………………………………………........................................

[2 marks]

Glucose

Compound P

C2H6O

Compound Q

Compound R

Reaction II

Reaction I

Chemistry Perfect Score/X A-Plus Module 2012 59

3. Diagram 3 shows a series of reactions involving compound Q, C2H6O.

Diagram 3

(a) (i) State the name of reaction I.

…………....……………………………………………………………………………….

[1 mark]

(ii) State the name of compound Q.

…………………………………………………………………………..........……………

[1 mark]

(iii) Draw the structural formula for compound Q.

[1 mark]

(b) Write a chemical equation for the complete combustion of compound Q.

…………………………………………………………………………………...……………

[2 marks]

(c) (i) State the name of gas R that produced in reaction III.

……………………………………………………………………………....…………….

[1 mark]

(ii) Draw the set-up of apparatus to carry out reaction III in the laboratory.

[2 marks]

(d) State the change of colour of acidified potassium manganate(VII) solution in reaction IV.

………………………………………………………………………………………………

[1 mark]

Glucose

Gas P

Compound Q, C2H6O Gas R

Compound S, C2H4O2 Compound T

Water

Yeast

Combustion

I

+ II III

pieces of porcelain

Acidified potassium

manganate(VII) solution IV

Concentrated sulphuric acid,

refluxed with compound Q.

V

Chemistry Perfect Score/X A-Plus Module 2012 60

(e) (i) State the name of reaction V.

………………………………………………………………………………………….

[1 mark]

(ii) State the name of compound T.

………………………………………………………………………………………….

[1 mark]

4. (a) The following flow chart shows the steps involved in the manufacture of an industrial

substance L and the production of fertiliser M.

(i) What is substance L?

………………………………………………………………………………………………….. [1 mark]

(ii) Name the industrial process to produce substance L.

………………………………………………………………………………………………….. [1 mark]

iii) What is substance K?

…………………………………………………………………………………………………...

[1 mark]

(iv) The conversion of sulphur dioxide to substance M is very slow. Catalyst and high temperature are

used to overcome these problems. State the catalyst and the temperature used.

…………………………………………………………………………………………………… [2 marks]

(v) What is fertiliser M?

………………………………………………………………………………………….

[1 mark]

(b) Table 4 shows the manufactured substances in industries.

Material Substance L Alloy Polymer Glass

Example Reinforced

concretes Bronze

Polyvinyl

chloride (PVC) Borosilicate

glass

Table 4

Based on Table 4, answer the following questions.

(i) State the name of substance L.

…………………………………………………………………………………………..

[1 mark]

(ii) Draw and label the arrangement of atoms in bronze.

[2 marks]

Chemistry Perfect Score/X A-Plus Module 2012 61

(iii) Write the chemical equation for the polymerisation process of Polyvinyl chloride.

….……………………………………………………………………………………….

[1 mark]

(iv) State one reason for borosilicate glass to use in laboratory glassware.

….……………………………………………………………………………………….

[1 mark]

5. (a) Soap can be prepared from the reaction between oil and concentrated sodium hydroxide.

Diagram 5 shows the equation for the reaction.

+ 3NaOH Soap Y +

R is a carbon chain with 15 carbon atoms.

(i) State what is soap.

…………………………………………………………………………………………………..

[1 mark]

(ii) Draw the structural formula for soap Y formed . On the diagram you have drawn , label the

hydrophobic and hydrophilic parts of the soap

[2 marks]

(iii) Name this reaction

……………………………………………………………………………………………………….

[1 mark]

(iv) During the preparation of soap, sodium chloride is added to the soap mixture. Explain why?

…………………………………………………………………………………………………

…………………………………………………………………………………………………

[1 mark]

CH2OH

O

R C O CH2

CH2OH

O

R C O CH2 CH2OH

O

R C O CH2

Diagram 5

Chemistry Perfect Score/X A-Plus Module 2012 62

(b) Medicine is often given to patients to cure or prevent diseases. The table below shows the examples of

four types of commonly used medicines. Medicine Example

Analgesics Aspirin Q Penicillin

Psychotherapeutic medicine P

(i) What is the function of analgesics medicines?

………………………………………………………………………..……………………………….. [1 mark]

(ii) What is the negative effect of taking aspirin. ………………………………………………………………………..……………………………….. [1 mark]

(iii) State the type of medicine for Q.

………………………………………………………………………..………………………………. [1 mark]

(iv) Why is it very important to follow the prescription and to complete the dosage when taking

penicillin?

………………………………………………………………………..………………………………..

………………………………………………………………………..……………………………….. [1 mark]

(v) State one example of P. ………………………………………………………………………..…………………………………

[1 mark]

Chemistry Perfect Score/X A-Plus Module 2012 63

SECTION B

6 (a) Table 6 shows some information about three members of a homologous series.

Member of

homologous series

Boiling

point (°C) Preparation Oxidation product

Ethanol 78 C2H4 + H2O → C2H5OH Ethanoic acid

Propanol 97 C3H6 + H2O → C3H7OH Propanoic acid

Butanol 118 C4H8 + H2O → C4H9OH Butanoic acid

Table 6

Based on Table 6, state and explain five characteristics of a homologous series. [10 marks]

(b) The following information is about an organic compound X.

Empirical formula is CH2O

Relative molecular mass is 60

Reacts with calcium carbonate to produce a type of gas that turns lime water chalky Based on the information given:

(i) State the molecular formula of X.

(Relative atomic mass : C = 12, H = 1, O = 16)

[2 marks]

(ii) State the name of the homologous series for X and explain your answer. [2 marks]

(iii) Write a balanced chemical equation for the reaction of compound X with calcium

carbonate. [2 marks]

(c) Diagram 6 shows the structural formulae of hydrocarbon of compounds P and Q.

Compound P Compound Q Diagram 6

Compare and contrast these two hydrocarbons based on their structures. [4 marks]

7. (a) A hydrocarbon M, consists of 85.7% of carbon and X% of hydrogen by mass.

[Relative atomic mass: C = 12; H = 1 , Relative molecular mass of M = 56.]

(i) What is the value of X.

[1 mark]

(ii) Determine the empirical formula and molecular formula of hydrocarbon X.

[5 marks]

(iii) Draw the structural of the two isomers of hydrocarbon M.

Write the names for each isomer

[4 marks]

(iv) Compound M burns with sootier flames as compared to butane.

Explain and prove.

[3 marks]

Chemistry Perfect Score/X A-Plus Module 2012 64

(b) Natural rubber is a natural polymer.

(i) Give another two examples of natural polymer.

[2 marks]

(ii) Name and draw the structural formula of the monomer of natural rubber.

[2 marks]

(c) The tyres of aircrafts are made from vulcanised rubber.

(i) What is vulcanised rubber?

[1 marks]

(ii) Explain why vulcanised rubber is more elastic than unvulcanised rubber.

[2 marks]

8 (a) Diagram 8.1 shows the structural formula of two of hydrocarbons.

Hydrocarbon A Hydrocarbon B

Diagram 8.1

(i) State the type of bond, homologous series and general formula of hydrocarbon A and

hydrocarbon B.

[6 marks]

(ii) Complete combustion of hydrocarbon A produces gas C and water.

State the name of gas C and write the chemical equation for the reaction.

[3 marks]

(iii) Which hydrocarbon change the colour of bromine water from brown to colourless. Explain

your answer.

[3 marks]

(iv) Diagram 8.2 shows the burning of hydrocarbon A and hydrocarbon B in air.

Compare the sootiness of hydrocarbon A and hydrocarbon B.

Explain your answer.

[Given that the relative atomic mass of H = 1, C = 12]

[4 marks]

Diagram 8.2

Porcelain dish

Filter paper

Soot

Hydrocarbon A Hydrocarbon B

Chemistry Perfect Score/X A-Plus Module 2012 65

(b) Diagram 8.3 shows the reaction between carboxylic acid X and alcohol Y.

Diagram 8.3

Draw the structural formula and state the name of carboxylic acid X and alcohol Y.

[4 marks]

9. (a) Sulphur dioxide, SO2, is one of the by-products of the Contact Process.

It can cause environmental pollution like acid rain.

Sulphur dioxide gas dissolves in rain water to produce sulphurous acid

(i) Write the chemical equation for the reaction between sulphur dioxide gas and rain water.

(ii) State three effects of acid rain to the environment.

[4 marks]

(b) Diagram 7 shows an industry preparation of sulphuric acid by the Contact Process.

Diagram 9

(i) Name the compound X.

(ii) Write the chemical equation of the reaction at stage II.

(iii) The chemical equation below shows the reaction between sulphur and oxygen gas

at stage I.

S + O2 SO2

Given that the relative atomic mass of S = 32, O = 16 and the molar volume of any gas is

24 dm3mol

-1 at room temperature and pressure.

Calculate the maximum volume of sulphur dioxide gas produced if 48 g of sulphur is burnt

completely in oxygen gas.

[6 marks]

(c) Brass is an alloy of copper. Pure copper is ductile and malleable whereas brass is stronger and harder

than copper.

(i) Explain why pure copper is ductile and malleable?

[5 marks]

(ii) Name the element which is added to copper to make brass. Explain why brass is strong and harder

than copper. Draw a diagram to show the arrangement of atoms in brass.

[5 marks]

S SO2 SO3 X H2SO4

Stage I Stage II Stage III Stage IV

Oxygen Oxygen Concentrated

sulphuric acid

Water

Carboxylic acid X

Alcohol Y

+ Water +

Chemistry Perfect Score/X A-Plus Module 2012 66

10. (a) Food preservatives are substances added to food so that the food can be kept for longer periods

for time. Using two suitable examples, explain how they work as preservative.

[4 marks]

(b) The following is the information about a child.

2 years old

High fever

Whooping cough

(i) Can aspirin be used to treat the child? Explain why. [2 marks]

(ii) Name two examples of modern medicine that can be used to treat the child .

[2 marks]

(iii) Explain the effect if the precautions states in (b)(ii) are not followed properly.

[2 marks]

(c ) Table 10 shows the food additives that are added to a certain food by two chefs.

Chef Wan Chef Koh Turmeric Sugar, salt and spice Garlic

Tartrazine Monosodium glutamate Ascorbic acid

Table 10

Based on Table 10, categorise the food additives. Include in your answer the function of each

type of food additives and the disadvantages of using any two food additives.

[10 marks]

Chemistry Perfect Score/X A-Plus Module 2012 67

SECTION C

11. (a) Table 11 shows the result of two sets of experiment to investigate the coagulation of latex.

Set Type of solution Observation

I Latex + solution X Latex coagulate very fast II Latex + solution Y Latex does not coagulate

Table 11

(i) Suggest one possible substance for solution X. and Y

[2 marks]

(ii) Explain the process of coagulation of latex in set I

[4 marks]

(iii) Explain why latex does not coagulate in set II

[2 marks]

(b) Diagram 11 shows how compound Q is formed from alkene W.

Diagram 11

(i) Name the homologous series of compound Q.

[1 mark]

(ii) State two chemical properties of compound Q.

[2 marks]

(iii) By using a compound Q with number of carbon atom per molecule more than one,

describe an experiment to convert compound Q to alkene.

Your answer should consist of the following:

Procedure of the experiment

A labelled diagram showing the apparatus set-up

The test to confirm the product is alkene

[9 marks]

Alkene W + H2O

Compound Q

Chemistry Perfect Score/X A-Plus Module 2012 68

12. Diagram 12.1 shows five structural formula of carbon compound.

Diagram 12.1

(a) Choose any one of the compound in Diagram 12.1, state the products formed when the

compound burn completely in excess oxygen gas.

Write the chemical equation involve.

[3 marks]

(b) State the name of two compounds in Diagram 12.1 that are isomer.

Explain your answer.

[3 marks]

(c) Describe a chemical test to differentiate between compound A and compound B.

[4 marks]

(d) Diagram 10.2 shows the reaction between compound E and carboxylic acid.

Diagram12.2

(i) State the name an example of a member of carboxylic acid and state the name of

ester that formed when the named carboxylic acid react with compound E.

Draw the structural formula of named carboxylic acid and ester that formed.

[4 marks]

(ii) Describe an experiment to produce ester in (d) (i) in laboratory.

[6 marks]

Compound E + Carboxylic acid → ester

Chemistry Perfect Score/X A-Plus Module 2012 69

13 (a) Diagram 13.1 shows a structural formula of butene,

Diagram 9.1

Draw structural formulae for another two isomers of butene and names each isomer according

to the IUPAC nomenclature.

[4 marks]

(b) Diagram 9.2 shows the structural formula of an ester

Diagram 13.2

Based on diagram 13.2:

(i) Identify the two organic chemicals needed to produce the ester above.

[2 marks]

(ii) State three chemical properties for each organic chemicals that you stated in 9(b)(i).

[6 marks]

(c) Diagram 13.3 shows the formula of two hydrocarbons P and Q :

P Q

Diagram 13.3

(i) State the name of hydrocarbons P and Q.

(ii) Describe two chemical tests to differentiate between hydrocarbon P and Q.

Your description must include the procedure and observation.

[8 marks]

C C C C H

H H H H

H

H H

C C C O H

H

H H

H H O

C

H

H

C H

H

CH3(CH2)4CH3 CH3(CH2)3CH = CH2

Chemistry Perfect Score/X A-Plus Module 2012 70

14 Diagram 14 shows the industrial manufacture of ammonia.

Diagram 14

(a) State the name of the above process, catalyst Y and write a chemical equation for the

reaction between hydrogen and nitrogen.

[4 marks]

(b) Table 14 shows the diameter of the dent formed in an experiment to compare the hardness of

copper and bronze.

Material Diameter /cm Copper 1.0 Bronze 0.5

Table 14

Based on Table 12, draw a diagram to shows the arrangement of atoms in pure copper and

bronze. Compare the hardness between copper and bronze and explain why.

[6 marks]

(c) The iron window frame of Encik Razali’s house rusts after several years but the steel window

frame of Encik Tarmizi’s house does not rust.

By using suitable examples, describe a laboratory experiment to compare the resistant to rust of

alloy compared to pure metal.

Include the following in your answer:

Procedure

Results

Conclusion

[10 marks]

Chemistry Perfect Score/X A-Plus Module 2012 71

15. (a) Table 15 shows the different types of traditional medicine and modern medicine.

Traditional medicine

Modern medicine

Garlic Quinine Lemon Aloe vera Ginseng Tongkat Ali

Aspirin Penicillin Paracetamol Codein Chloropromazin Caffeina

Table 13

(i) What are the differences between traditional medicine and modern medicine?

[2 marks]

(ii) Modern medicines can be classified as analgesics, antibiotics and psychotherapeutic drugs.

Group the medicines in Table 2 into these three different classes.

[5 marks]

(iii) State the side effects of penicillin, codeine and aspirin.

[3 marks]

(b) State what is hard water and give an example of hard water.

You are required to carry out a laboratory activity to investigate the effectiveness of

cleansing action of soap and detergent in hard water. Your answer should consist of the

following:

Procedure

Observation

Conclusion

[10 marks]

Chemistry Perfect Score/X A-Plus Module 2012 72

CHEMISTRY MODULE

SET 5

1. PAPER 3 SET 1

2. PAPER 3 SET 2

3. PAPER 3 SET 3

4. PAPER 3 SET 4

5. PAPER 3 SET 5

Chemistry Perfect Score/X A-Plus Module 2012 73

PAPER 3 SET 1

1. Diagram 1.1 shows the set-up of apparatus for an experiment to compare the hardness of a metal and its

alloy.

A steel ball bearing is taped onto the copper block using cellophane tape. A weight of 1 kilogram is dropped at

a height of 50 cm to hit the ball bearing. The diameter of the dent made on the copper block is measured. The

experiment is repeated by replacing copper block with bronze block.

Table 1.1 shows the view of the dents made on bronze and copper block

(a) (i) By using the ruler given, measure the diameters of the dents made on copper and

bronze blocks. Record all the diameters of the dents in Table 1.1.

[3 marks]

Experiment Bronze Copper

I

II

III

Diagram 1.1

Copper block

Retort stand

Thread

Weight

Meter ruler

Steel ball

bearing

Diameter: ............. Diameter: .................

Diameter: .................

Diameter: .................

Table 1.1

Diameter: .................

Diameter: .................

Chemistry Perfect Score/X A-Plus Module 2012 74

(ii) Construct a table to record the diameters of the dents and average diameter of the dent on

copper and bronze blocks.

[3 marks] (b) State one observation that can be obtained from this experiment.

............................................................................................................................. .............

………………………………………………………………………………..…………

[3 marks]

(c) Based on the average diameter of the dents on copper and block, state the inference that can be made.

............................................................................................................................. .............

…………………………………………………………………………………………

[3 marks]

(d) State the operational definition of the hardness of bronze.

............................................................................................................................. .............

…………………………………………………………………………………………

[3 marks]

(e) Explain why there is difference in diameter of dents on copper and bronze blocks.

............................................................................................................................. .............

…………………………………………………………………………………………

[3 marks]

(f) State the hypothesis for this experiment.

............................................................................................................................. .............

..…………………………………………………………………………………………

[3 marks]

(g) Complete table 1.2 based on the experiment.

Name of variables Action to be taken

(h) Manipulated variable:

(i)The way to manipulate variable:

(ii) Responding variable:

(ii) What to observe in the responding variable:

(iii) Controlled variable: (iii) The way to maintain the control variable:

[3 marks]

Table 1.2

Chemistry Perfect Score/X A-Plus Module 2012 75

2. The table 2.1 below shows the set-up of apparatus of the experiment to investigate the effect of copper,

magnesium and zinc on the rusting of iron. A mixture of jelly solution, potassium hexacyanoferrate(III)

solution and phenolphthalein were used as medium in each test tube. The observations were recorded

after one day.

Test tube A

Iron nail coiled with

copper

Test tube B

Iron nail coiled with

magnesium

Test tube C

Iron nail coiled with

zinc

Test tube D

Iron nail

(a) State the inference for the observation in test tube A, B, C and D.

Test tube Inference

A

B

C

D

[3 marks]

(b) Based on this experiment, explain why there is a difference in the observation between test tube A

and test tube B.

…………………………………………………………………………………………

.………………………………………………………………………………………. [3 marks]

Table 2.1

Low intensity of

blue colour

Low intensity of

pink colour

High intensity of pink colour

High intensity

of blue colour.

Chemistry Perfect Score/X A-Plus Module 2012 76

(c) State the hypothesis for the experiment.

………………………………………………………………………………………….

………………………………………………………………………………………….

[3 marks]

(d) Based on this experiment state:

(i) The manipulated variable:

…..…………………………………………………………………………….........

(ii) The responding variables:

………………………..………………………………………………………………

(iii) The constant variables:

…………………………….…………………………………………………………..

[3 marks]

(e) State the operational definition for the rusting of iron nail.

………………………………………………………………………………………………

………………………………………………………………………………………………[3 marks]

(f) Based on this experiment classify the metals that can provide sacrificial protection and metal cannot

provide sacrificial protection to iron.

[3 marks]

(g) Observation in test tube D is recorded after two days

After one day After two days

Compare the observation for the experiment in the first day and the second day

Explain your answer.

………………………………………………………………………………………….

………………………………………………………………………………………….

[3 marks]

Chemistry Perfect Score/X A-Plus Module 2012 77

ESAY / PLANNING

3. Different type of alcohols produces different heat of combustions when burnt in oxygen. When the

number of carbon per molecule of alcohol increases, the heat of combustion also increases. Table 3.1

shows the heat of combustion of ethanol, propanol and butanol.

Alcohol Molecular formula Heat of combustion/ kJ mol-1

Ethanol C2H5OH -1376

Propanol C3H7OH -2016

Butanol C4H9OH -2678

Plan a laboratory experiment to investigate the relationship between type of alcohols and the heat of combustion

produced. Your planning must include the following aspects:

(a) Statement of the problem

(b) All the variables

(c) Hypothesis

(d) List of materials and apparatus

(e) Procedure

(f) Tabulation of data

[17 marks]

PAPER 3 SET 2

1. A student carried out an experiment to determine the end-point for the titration of 25.0 cm3 of 1.0 mol

dm-3 sodium hydroxide solution with hydrochloric acid. Phenolphthalein is used as the acid-base

indicator. Table 1 shows the three titrations that were conducted and the magnification of the burette

readings.

Titration No.

I II III

Initial burette

reading

………………………..

…………………………..

……………………………..

Final burette

reading

…..……………………

….……………………

…..…………………….

Table 1

Table 3.1

hydrochloric

acid

27

26

7

hydrochloric

acid

39

38

hydrochloric acid

14

13

hydrochloric

acid

27

26 hydrochloric

acid

2

1 hydrochloric

acid

14

13

Chemistry Perfect Score/X A-Plus Module 2012 78

(a) Record the burette readings for the three titrations in the spaces provided in Table 1.

[3 marks]

(b) Construct a table and record the initial burette reading, final burette reading and the volume of acid

used for each titration.

[3 marks]

(c) Calculate the molarity of the hydrochloric acid used in the experiment.

[ 3 marks]

(d) The experiment is repeated by replacing hydrochloric acid 1.0 mol dm-3

with sulphuric acid 1.0 mol dm-3

.

(i) Predict the volume of sulphuric acid needed to neutralise the sodium hydroxide solution.

............................................................................................................................. .

(ii) Explain your answer for (d) (i).

……......................................................................................................................

……......................................................................................................................

[3 marks]

Chemistry Perfect Score/X A-Plus Module 2012 79

(e) Table 1 shows the results of an experiment to investigate the relationship between the pH values of

acids and the strength of acid.

Solution pH value

Hydrochloric acid, 1.0 mol dm-3

2.0

Ethanoic acid, 1.0 mol dm-3

5.0

Table 1

For this experiment, state

(i) The manipulated variable

............................................................................................................................. .............

(ii)The responding variable

……........................................................................................................................... .......

(iii) The fixed variable

……..................................................................................................................................

[3 marks]

(g) State one hypothesis for this experiment.

………………………………………………………………………………………………………………

……………………………….…………………………………………………………………………………………

[3 marks]

(h) Classify the following substances into substances with pH value less than 7 and pH value more than 7.

Ethanoic acid Barium hydroxide

Ammonia solution Nitric acid

[3 marks]

Chemistry Perfect Score/X A-Plus Module 2012 80

2. Diagram 2.1 shows the apparatus set up for the preparation of ester in the laboratory.

Table 2.1 show some examples of the types of alcohol and carboxylic acid used to prepare ester.

Alcohol Carboxylic Acid Observation

Methanol Ethanoic acid Sweet pleasant smell

Ethanol Propanoic acid Sweet pleasant smell

Propanol Methanoic acid Sweet pleasant smell

Table 2.1

(a) State one inference for this experiment.

………………………………………………………………………………………………………

…………………………………………………………………………………………………………

…………………………………………………………………………………………………….…

[3 marks]

(b) Construct a table to show the name of the esters formed from the alcohols and carboxylic acids

provided in Table 2.1

[3 marks]

(c) Propyl butanoate is an ester that is formed from the reaction between an alcohol and carboxylic

acid.

Name the alcohol and carboxylic acid needed to prepare the ester.

Alcohol:

............................................................................................................................. .......

Carboxylic acid:

........................................................................................................................... ..............................

[3 marks]

heat

water in

water out

Mixture of alchohol +

carboxylic acid and a

few drops of

concentrated sulphuric

acid

Diagram 2.1

Chemistry Perfect Score/X A-Plus Module 2012 81

(d) Table 2.2 shows the observation for an experiment to differentiate between alkanes and alkenes.

Experiment Hexane Hexene

With bromine water No change

Brown bromine

decolourised

With acidified potassium

manganate (VII) solution

No change Purple solution

decolourised

Table 2.2

(i) State the variables for this experiment:

Manipulated variable:

……………….............................................................................................

Responding variable:

…………………………................................................................................

Fixed variable:

……........................................................................................................................

[3 marks]

(ii) State one hypothesis for this experiment.

….…………………………………………………………………………………

…...…………………………………………………………………………………

[3 marks]

(iii) Hexene can also be differentiated from hexane with sootiness of flame when burnt.

Predict which substance will produce more soot when burnt. Explain your answer.

….…………………………………………………………………………………

……………………………………………………………………………………

[3 marks]

Chemistry Perfect Score/X A-Plus Module 2012 82

3. Diagram 3 shows the set-up of apparatus used to investigate the cleansing action of soap and detergent

on a piece of cloth stained with oil.

Based on the above diagram, plan one laboratory experiment tocompare the effectiveness of soap and

detergent in hard water.

Your planning should include the following aspects:

(a) Problem statement

(b) All the variables

(c) Statement of the hypothesis

(d) List of substances and apparatus

(e) Procedure of the experiment

(f) Tabulation of data

[17 marks]

END OF QUESTION PAPER

Chemistry Perfect Score/X A-Plus Module 2012 83

SET 3

1. Diagram 1.1 shows the set-up of apparatus and thermometer reading for the experiment to compare the

heat of combustion of four alcohols, methanol (CH3OH), ethanol (C2H5OH), propanol (C3H7OH) and

butanol (C4H9OH). The initial and final mass of the spirit lamp containing alcohol is weighed and

recorded. The alcohols is used to heat 200 cm3 of water .

Diagram 1.1

(a) Based on Diagram 1.1,

(i) Record the initial and highest reading of the thermometer in the spaces provided.

[3 marks]

(ii) State one observation

............................................................................................................................. ..........................[3 marks]

(iii) Give one inference based on the observation in (a)(ii).

............................................................................................................................. .............

[3 marks]

Thermometer

Water

Initial temperature:.........................

Methanol

Copper tin

Wind shield

Highest temperature:...................

Methanol

Thermometer

Copper tin

Water

Wind shield

Chemistry Perfect Score/X A-Plus Module 2012 84

(b) Diagram 1.2 shows the initial and final reading of the electronic balance for the mass of spirit lamp

before burning and after burning of four alcohols.

Alcohol Initial reading (g) Final reading (g) Mass of alcohol used (g)

Methanol

Ethanol

Propanol

Butanol

Diagram 1.2

Based on Diagram 1.2,

(i) State the mass of the alcohols used in space provided into two decimal places.

[ 3 marks]

(ii) Tabulate the initial mass, final mass and mass of alcohol used for the four alcohols in this experiment.

[3 marks]

(c) Calculate the heat of combustion of methanol.

[Specific heat capacity of water = 4.2 J g-1 oC-1]

[3 marks]

ON

OFF 354.9548 g ON

OFF 353.4012 g

ON

OFF 339.7892 g

ON

OFF 364.4303 g ON

OFF 360.8702 g

ON

OFF 332.9891 g ON

OFF 328.9790 g

ON OFF 342.0201 g

Chemistry Perfect Score/X A-Plus Module 2012 85

(d) Table 1.1 shows the heat of combustion of ethanol (C2H5OH), propanol (C3H7OH) and butanol

(C4H9OH).

Alcohol Molecular Formulae Heat of combustion/kJ mol-1

Ethanol C2H5OH 970

Propanol C3H7OH 1400

Butanol C4H9OH 1860

Table 1.1

For this experiment, state:

(i) The manipulated variable.................................................................................

The responding variable.....................................................................................

The fixed variable...............................................................................................

[3 marks]

(ii) State one hypothesis for this experiment.

............................................................................................................................. ....................

............................................................................................................................. ....................

.................................................................................................................................................

[3 marks]

(e) If the experiment is repeated using pentanol, predict the heat of combustion of pentanol.

.................................................................................................................................................

[3 marks].

(f) The actual heat of combustion for ethanol is 1376 kJ mol-1.

State three reasons why the experimental value heat of combustion for ethanol is less than the actual

value.

1. ....................................................................................................................................

2. ............................................................................................................................. .......

3. ............................................................................................................................. .......

[3 marks]

(g) Table 1.2 shows the list of carbon compounds and their molecular formula.

Carbon compound Molecular formula

Hexene C6H12

Propanoic acid C2H5COOH

Ethanol C2H5OH

Methane CH4

Table 1.2

Classify the above carbon compounds into hydrocarbon and non hydrocarbon.

[3 marks]

Chemistry Perfect Score/X A-Plus Module 2012 86

2. Diagram 2.1 and 2.2 show Experiment I and Experiment II to investigate the effect of type of electrodes

on the products formed at the electrodes.

Experiment I

Experiment II

Based on Diagram 2.1 and Diagram 2.2 above, plan a laboratory experiment to investigate the effect of the type

of electrode to the product at anode.

Your answer should consist of the following:

(a) Aim of experiment

(b) All the variables

(c) Hypothesis

(d) List of materials and apparatus

(e) Procedure

(f) Tabulation of data

[17 marks]

Diagram 2.1

After 30 minutes

Carbon

electrodes

Carbon

electrodes

After 30 minutes

Copper electrodes

0.01 mol dm-3

copper(II)

chloride solution

Diagram 2.2

Chemistry Perfect Score/X A-Plus Module 2012 87

SET 4

1. The experiment is carried out using a small piece of lithium and potassium to react with oxygen gas. The

set-up of apparatus and observations of reaction are shown in Table 1.1

Set

Set-up of apparatus

Observation

I

Burns slowly and produces white

fumes.

II

Table 1.1

(a) Complete the Table 1.1 by stating the observation for reaction of potassium metal towards oxygen.

[3 marks]

(b) Based on the Table 1.1, state the relationship between the positions of element of Group 1 with the

reactivity of the elements towards oxygen gas.

………………………………………………………………………………….…………..……

…………………………………………………………………………………….…………….

[3 marks]

(c) After the reaction in Set I stopped, the gas jar is filled with water and a few drops of

phenolphthalein solution is added. The colourless solution formed change to pink.

Give one inference based on the observation above.

……………………………………………………………………………………..........

[3 marks]

White fumes

Lithium

White fumes

Potassium

Chemistry Perfect Score/X A-Plus Module 2012 88

(d) The experiment is repeated by using X metal to react with oxygen. The result of the experiment is

shown in Table 1.2.

Table 1.2

Predict the position of X metal in the Periodic Table of elements.

………………………………………………………………………………….………

…………………………………………………………………………………….…….

[3 marks]

(e) Lithium hydroxide solution is produced when lithium oxide reacts with water.

Classify the ions that exist in the solution into cation and anion.

[3 marks]

Set-up of apparatus Observation on the metal

Burns rapidly and produces white

fumes.

Cation Anion

White fumes

X metal

Chemistry Perfect Score/X A-Plus Module 2012 89

2. An experiment was carried out to construct an electrochemical series of metals. Diagram 2.1 shows the

set-up apparatus for an experiment the chemical cell to measure the potential difference between

electrode Copper metal and metal M. An experiment was repeated by replacing metal M with

metal J and Q.

Diagram 2.1

A B

C

Diagram 2.2

Diagram 2.2 shows the potential difference of three voltmeters A, B and C for the chemical cells with pair

of metal Cu/M, Cu/J and Cu/Q respectively.

i)

Pair of Metals

Voltmeter

Potential

difference(V)

Positive

terminal

Cu and M A Cu

Cu and J B Cu

Cu and Q C Q

Table 1

(a) Record the voltmeter reading for the pairs of metal in the Table 1.

[ 3 marks]

0

1.0 2.0

3.0

0.5

1.5

2.5 V

·

0

1.0 2.0

3.0

0.5

1.5

2.5

V ·

0

1.0 2.0

3.0

0.5

1.5

2.5 V

·

V

copper metal metal M

Copper( II )

sulphate solution

1.0 mol dm-3

Chemistry Perfect Score/X A-Plus Module 2012 90

(b) State the hypothesis of the experiment

........................................................................................................................................................ .........

...........................................................................................................................................

[ 3 marks ]

(c) Arrange J, Cu, M and Q metals in the descending order in the electrochemical series

............................................................................................................................. ..............

[ 3 marks ]

(d) Iron metal is located between metal M and copper metal in the electrochemical series. State which

metals are more electropositive and less electropositive than iron metal.

More electropositive than iron:

............................................................................................................................. ..............

Less electropositive than iron

............................................................................................................................. ............

[3 marks]

(e) Diagram 2.2 below shows simple voltaic cell using Cu and metal J before and after an experiment.

Copper(II) sulphate

Solution (blue colour)

Copper Metal J

Before experiment

After experiment

Diagram 2.3

V

V

Metal J

Copper(II) sulphate Solution (light blue)

Copper

Chemistry Perfect Score/X A-Plus Module 2012 91

State three observations shown in Diagram 2.3

1. ……………………………………………………………………………………......

2. …………………………………………………………..……………………………

3. …………………………………………………………..……………………………

[3 marks]

3. Reaction between sodium thiosulphate, Na2S2O3 solution and dilute sulphuric acid, H2SO4 will produce

sodium sulphate, Na2SO4, sulphur, S, sulphur dioxide, SO2 and water, H2O. The chemical equation is:

Na2S2O3 + H2SO4 Na2SO4 + S + SO2 + H2O

By using the information above, plan an experiment to investigate the effect of temperature on the rate of

reaction. Your planning should include:

Your planning should include the following aspects:

(a) Problem statement

(b) All the variables

(c) Statement of the hypothesis

(d) List of substances and apparatus

(e) Procedure of the experiment

(f) Tabulation of data

[17 marks]

Chemistry Perfect Score/X A-Plus Module 2012 92

SET 5

1. Diagram 1.1 shows the conversation between a student and his teacher.

Diagram 1.1

Based on Diagram 1.1, an experiment was carried out using glacial ethanoic acid and ethanoic acid in

two different solvents. Table 1 shows the results of the experiment when tested with blue litmus

paper.

Experiment State of ethanoic acid Observation on blue

litmus paper

I Glacial ethanoic acid No change

II Ethanoic acid in water Blue to red

III Ethanoic acid in dry propanone, No change

Table 1

(a) State one inference for this experiment.

..........................................................................................................................................

.........................................................................................................................................

.........................................................................................................................................

[3 markah]

(b) Explain the difference in observation for Experiment II and III.

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

[3 mark]

(c) Based on the experiment, state

Manipulated variable:

........................................................................................................................................

Responding variable:

……………………........................................................................................................

Fixed variable:

……………….................................................................................................................

[3 marks]

Chemistry Perfect Score/X A-Plus Module 2012 93

(d) State one hypothesis for this experiment.

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

[3 marks]

(e) Diagram 1.2 shows the experiment to investigate which solvent can cause an alkali to exhibit

its alkaline properties.

.Diagram 1.2

(i) State the observation in Diagram 1.2.

Test tube I: ...............................................................

Test tube II: .............................................................

Test tube III: ........................................................... [3 marks]

(ii) Construct a table to record the observation for experiment I, II and III.

[3 marks]

(f) Classify the following substances into substances that can change moist blue litmus paper to

red and substances that can change moist red litmus paper to blue.

Calcium hydroxide Phosphoric acid

Oxalic acid Barium hydroxide

Ammonia aqueous Sulphurous acid

[3 marks]

I II III

Chemistry Perfect Score/X A-Plus Module 2012 94

2. Diagram 2 shows Step I and Step II in an experiment to construct an ionic equation for the

formation of barium chromate(VI).

Step I:

Step II:

Diagram 2

0.5 mol dm-3

barium chloride, BaCl2 solution was added to each test tube containing 5.0 cm3

potassium chromate(VI), K2CrO4 solution according to the volumes shown in Step II. Each test

tube is stopper and shaken well. Yellow precipitate of barium chromate(VI) is formed.

0.5 mol dm-3

potassium

chromate (VI)

solution

0.5 mol dm-3

barium chloride

solution

5 cm3 5 cm

3 5 cm

3 5 cm

3 5 cm

3 5 cm

3 5 cm

3

Yellow precipitate

1 cm3

2 cm3

3 cm3 4 cm

3 5 cm3

6 cm3

7 cm3

Chemistry Perfect Score/X A-Plus Module 2012 95

Table 2 shows the results for this experiment.

Test tube

1 2 3 4 5 6 7

Volume of 0.5 mol dm-3

barium chloride solution/cm3 1.0 2.0 3.0 4.0 5.0 6.0 7.0

Height of barium chromate

(VI) precipitate/cm

Table 2

(a) Using a ruler, measure the height of yellow precipitate in test tube 1 to 7 and record the height

of the precipitate in Table 2.

.

[3 marks]

(b) Draw a graph of height of precipitate against volume of barium chloride on the graph paper

provided.

[3 marks]

Chemistry Perfect Score/X A-Plus Module 2012 96

Question 2(b)

Chemistry Perfect Score/X A-Plus Module 2012 97

(c) Based on the graph above, state the volume of barium chloride solution 0.5 mol dm-3

which

react completely with 5 cm3 of potassium chromate(VI) solution and calculate the number of

mole of barium chloride solution is needed to react completely with

1 mole potassium chromate(VI) solution.

[3 marks]

(d) Write an ionic equation for the reaction between potassium chromate(VI) solution and barium

chloride solution.

…………………………………………………………………………………………..

[3 marks]

(e) State the operational definition for the precipitation of barium chromate(VI)

…………………………………………………………………………………………..

…………………………………………………………………………………..............

…………………………………………………………………………………………..

[3 marks]

(f) Classify the following salts into soluble salts and insoluble salts.

.

Soluble salts Insoluble salts

[3 marks]

Sodium carbonate, Na2CO3 Lead(II)sulphate, PbSO4

Silver chloride, AgCl Magnesium nitrate, Mg(NO3)2

Chemistry Perfect Score/X A-Plus Module 2012 98

3. Diagram 3.1 shows how latex is obtained from the rubber tree. Rubber is used to manufacture

substances for everyday life such as gloves and tires.

Diagram 1.3

An acid is used to coagulate latex while alkali can prevent the coagulation of latex. Based on this idea,

plan a laboratory experiment to investigate the effect of acid and alkali on the coagulation of latex.

Your planning should include the following aspects:

(a) Problem statement

(b) All the variables

(c) Statement of the hypothesis

(d) List of substances and apparatus

(e) Procedure of the experiment

(f) Tabulation of data

[17 marks]

END OF QUESTION PAPER