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Chemistry Perfect Score Module 2009 1 BAHAGIAN PENGURUSAN SEKOLAH BERASRAMA PENUH DAN SEKOLAH KLUSTER MODUL PERFECT SCORE  2009 CHEMISTRY Set 1 Set 2 Set 3 Set 4

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    Chemistry Perfect Score Module 2009 1

    BAHAGIAN PENGURUSANSEKOLAH BERASRAMA PENUH DAN SEKOLAH KLUSTER

    MODUL PERFECT SCORE2009

    CHEMISTRY

    Set 1 Set 2 Set 3 Set 4

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    Chemistry Perfect Score Module 2009 2

    CHEMISTRY PERFECT SCORE MODULE 2009

    CONTENT

    1Guidelines &

    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 and 3 The common diagram

    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

    Question Validation Panel Pn Wan Noor Afifah Bt Wan Yusoff (SBPI Gombak)

    En Che Malek Bin Mamat (SBPI Batu Rakit)

    Pn Foo Koi Hoon (SMS Seri Puteri)

    Pn Faridah Bt Hamat (SMS Seremban)

    Pn Masodiah Bt Mahfodz (SMS Hulu Selangor)

    Question Construction Panel

    1 En Che Ramli bin Che Ismail SMSTFP

    2 En Che Malik bin Mamat SBPI BR

    3 Pn Saadah binti Mohayuddin SMSSP

    4 En Jong Kak Ying SMS Kuching

    5 Pn Foo Koi Hoon SSSP

    6 En Muhammad Arif bin Sawiran SMSAS

    7 Pn Aishah Peong binti Abdullah SBPIT

    8 Pn Lim Ai [email protected] Irene SMSS Selangor

    9 Pn Wan Noor Afifah binti Wan Yusoff SBPI Gombak

    10 Pn Norini binti Jaafar SAS

    11 En Ooi Yoong Seang SMS Muar

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    Chemistry Perfect Score Module 2009 3

    CHEMISTRYPERFECT SCORE MODULE

    GUIDELINES

    &&&&

    ANSWERING TECHNIQUES

    CHEMISTRY SPM

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    Chemistry Perfect Score Module 2009 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 ItemSection B :Essay restricted response ItemSection C :

    Essay extended response Item

    Subjective Item :Structured ItemExtended 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 - - 50Total 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 atom2. Chemical Formulae And Equations3. Periodic Table4. 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 diagram6. 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 = 140/2

    =70 -1A)4.0 GUIDELINE FOR ANSWERING PAPER 1

    4.1 Paper 1 questions test students on1. Knowledge ( Number 1 20)2. Understanding ( Number 21 35)3. Application ( Number 36 50 )

    4.2 Score in paper 1 Indicates students level of understanding in chemistry:

    Less than 20 very weak20 25 - weak26 30 - average31 39 - good40 45 - very good46 50 - excellent.

    4.3 Answer all SPM objective question ( 2003 2008). Objective questions for each year contain all topics. Ifyour score in paper 1 is 40 and above, you will able to answer questions in paper 2 & 3 easi ly.

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    5.0 GUIDELINE FOR ANSWERING PAPER 2 ( STRUCTURE AND ESSAY)

    5.1 Paper 2 questions test student on1. Knowledge2. understanding3. analyzing4. 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 onInclude a labeled diagram in your answer1. Diagram2. Procedure3. Observation/example/data/calculation/equation/sketch of graph/conclusion

    II. Type 2Describe an experiment( The diagram will support your answer.)

    1. No mark is allocated for a diagram2. Procedures3. Observation/example/calculation/equation/sketch of graph/conclusion

    III. Type 3Describe a chemical/confirmatory test for .1. Procedure

    2. Observation3. Conclusion

    6.0 GUIDELINE FOR ANSWERING PAPER 3

    6.1 Structure Question 1/2 Test The Mastery of 11 Scientific Skills1. 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

    9. Defining Operationally10. Controlling Variables

    11. Hypothesizing

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

    6.2 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 situationgiven.

    State all the variables

    Manipulated variable :

    Responding variable :

    Constant variable : list down all the fixed variables to ensure the outcome of the responding variableis related only to the manipulated variables.

    Separate the substances and apparatus

    Procedure :

    All the steps taken in the procedure must include the apparatus used, quantity and type ofsubstance ( powder, solution, lumps etc).

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    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 respondingvariables

    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 thequestions requirement.

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

    Command word Explanation/example

    Name/State thename

    (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

    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

    State theobservation

    (Paper 2 & 3) 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 colourlessCorrect 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 hydrogenCorrect answer: A compound that contains carbon hydrogen only

    Describe chemicaltest(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 cm

    3of the solution in a test tube. Add a few drops of sodium

    hydroxide solution and the test tube is shake the test tube .........1- A reddish brown precipitate formed. .........1- Fe

    3+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 anexperiment( 8 - 10 marks)(Paper 2)

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

    - 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 anexperiment( 17 marks)( Paper 3)

    Answer the question according the requirement :

    Problem statement/Aim of experiment

    Hyphotesis

    Variables

    Can be obtained from the diagram

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    List of substances and apparatus

    Procedure

    Tabulation of dataNote: 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 theprocess Describe thestructure .Describeand writeequation

    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 factsExample: Experiment 1 is repeated using a larger beaker.Predict the increase in temperatureAnswer : 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/situationsExample : State three differences between ionic and covalent compound.Answer : State three properties of ionic compound and three properties covalent compound

    Draw a labeleddiagram of theapparatus(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 toshow the bondingformed in thecompound(Paper 2)

    (i)Ionic compound The number of electrons in each shell is correct, 2 electrons in the first shelland 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 and8 electrons in the second and third shell.

    The number of atoms sharing pair of electrons is correct.

    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 of the size of the graphpaper.

    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 tangentCalculate the gradient of the tangent

    Draw the energylevel 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 thearrangement ofparticles in solid,liquid and gas.(Paper 2)

    Solid : Draw at least three layers of particles closely packed in orderly manner and the are notoverlap.

    Liquid : The particles packed closely but not in orderly manner

    Gas : The particles are very far apart from each other

    Draw the direction ofelectron flow(Paper 2 /3)

    Draw the direction for the flow of electrons on the circiut, 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.

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    8.0 THE COMMON DIAGRAM IN CHEMISTRY SPM SYLLABUS

    Labelled Diagram for the Setup of Apparatus/ Structural Formula

    Determination Melting Point Determination of Freezing Point

    The Structure OfAtom

    Determination ofmelting and boilingpoint of naphthalene

    Particle arrangementin solid , liquid andgas

    Solid Liquid Gas

    Chemical Formulaeand EquationsDetermination ofempirical formula

    Magnesium oxide Copper(II) oxide

    Periodic TableReaction between sodium/potassium with oxygen

    Reactions between chlorine gas and iron

    Chemical Bond Theelectron arrangementin ionic and covalentcompound.* Make sure you canexplain the formationof the bondsaccurately

    .

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    Sodium chloride Magnesium chloride

    Tetrachloromethane Carbon dioxide

    Electrochemistry

    Electrolysis

    Molten Lead (II )bromide Copper(II) sulphate solution (Copper electrode)

    Sulphuric Acid ,Potassium sulphateHydrochloric acid( gas bubbles released ) Electroplating an iron key

    Purifying an impure metal

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    Voltaic cell

    Simple cell Daniell cell (porous pot)

    Daniell cell (Salt bridge )

    ACID ,BASE &SALT

    1. Heating ofcarbonatecompound andconfirmatory testfor carbon dioxide

    2. Preparation ofsoluble salt(Method I & II)

    3. Preparation ofinsoluble salt

    1.Heating of copper(II) carbonate and confirmatory test for carbon dioxide

    2. Preparation of soluble salt (Method I) Sodium nitrate

    3.Preparation of soluble salt (Method II) Copper(II) sulphate

    4. Preparation of insoluble salt Lead(II) iodide

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    H CH3

    C = C

    H HPropene Polypropene

    H Cl H Cl H

    C C C C C

    H H H H H

    Chloroethane Polivinly chloride(PVC)

    ManufacturedSubstances inindustry

    Polymerisation

    AlloysArrangement ofatoms in a metaland an alloy

    Arrangement of atoms in a pure metal Arrangement of atoms in alloy(Bronze)

    Rate of reaction Gasis collected usingwater displacementfor carbon dioxidegas, oxygen andhydrogen

    Redox1.Usage of tube U ,

    oxidising agent :a. Chlorine

    Waterb. Bromine

    Waterc. Potassium

    manganate (VII)acidified

    Reduction agent

    a.KIb.KBrc.FeSO4

    * Mark the positiveand negative terminal

    2.Rusting of iron

    Diagram to show the rusting of iron

    Iron

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    Thermochemistry

    Determination ofHeat Combustion

    Carbon Compound

    Alcohol Dehydration

    Oxidation of alcohol and esterification through reflux

    Alcohol Dehydration Oxidation of alcoholand esterification through reflux

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    CHEMISTRY PERFECT SCORE MODULE

    SET

    1. The Structure of Atom

    2. Chemical Formulae and Equations3. Periodic Table of Elements4. Chemical Bonds

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    PAPER 2 STRUCTURESECTION A

    1 Graph 1 shows the cooling curve of molten naphthalene beginning from 90oC.

    Table 1Based on Table 1, answer the following question.

    (a) State the melting point of naphthalene.

    [1 mark]

    (b) State the time when all the liquid naphthalene has frozen .

    .[1 mark]

    (c) Why does the temperature of naphthalene remains constant from t1 to t2?

    ..

    [2 marks](d) (i) What is the type of particles in naphthalene?

    [1 mark](ii) Draw the arrangement of particles of naphthalene at point P and R in the space provided.

    Point P Point R[2 marks]

    (e) State the physical state of naphthalene during the time

    (i) t1 to t2: .

    (ii) t2 to t3: ..

    [2 marks](f) When solid naphthalene is heated with direct flame and the physical state of naphthalene changes from

    solid to gas. Name the process that occurs.

    .

    Tem erature/C

    90

    PT

    0 t1 t2t3

    Time/min

    R

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    [1 mark]2 Table 2 shows four substances and their respective formulae

    Table 2(a) State all substances that exist as molecules.

    ..[1 mark]

    (b) Which substance is an electrolyte?

    [1 mark]

    (c) What is the physical state of bromine at room temperature?

    [1 mark]

    (d) State the substance that can conduct electricity in solid state

    [1 mark](e) Draw the arrangement of the particles in the substance in (d) at room temperature.

    [1 mark](f) Name the particles present in sodium chloride.

    [1 mark]

    (g) Graph 2 shows the temperature against time when solid phenol is heated.

    Graph 2(i) State the melting point of phenol.

    .

    [1 mark](ii) Explain why there is no change in temperature from Q to R.

    .

    .

    [2 mark](iii) State how the movement of naphthalene particles changes between R and S during the heating.

    ..[1 mark]

    Substance Chemical Formula

    Bromine Br2

    Nickel Ni

    Phenol C6H5OH

    Sodium chloride NaCl

    Tem erature/ C

    Time/s

    T0

    T1

    P

    Q R

    S

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    3 Diagram 3 shows the set -up apparatus of an experiment to determine the empirical formula of copper(II) oxide.

    Diagram 3

    (a) What is the meaning of chemical formula?

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

    [1 mark](b) State one precaution that must be taken before the copper (II) oxide is heated.

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

    (c) Table 3 shows the results of an experiment carried out by a student.

    Mass of combustion tube + porcelain dish 30.24g

    Mass of combustion tube + porcelain dish + copper (II) oxide 32.26g

    Mass of combustion tube + porcelain dish + copper 31.86g

    Table 3(i) Calculate the number of moles of copper in this reaction.

    [Relative atomic mass : Cu = 64]

    [1 mark](ii) Calculate the number of moles of oxygen in this reaction.

    [Relative atomic mass : O = 16]

    [1 mark](iii) Determine the empirical formula of copper (II) oxide.

    [2 marks](d) Name another metal oxide that uses the same method to determine the empirical formula.

    ...[1 mark]

    (e) M is a reactive metal. State how to determine the empirical formula of the oxide of M.

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

    Copper(II) oxide

    Heat

    Anhydrous calcium chloride, CaCl2

    Hydrogen gas

    Porcelain dish

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    4 Diagram 4 shows the apparatus set-up to determine the empirical formula of oxide metal M.

    DIAGRAM 4

    (a) (i) Name two chemicals used to prepare hydrogen gas in the laboratory.

    ...................................................................................................................................[2 marks]

    (ii) Write a chemical equation for the reaction in (a)(i).

    ....[1 mark]

    (b) Table 2 shows the result of the experiment:

    Mass of combustion tube + asbestos paper 39.25 g

    Mass of combustion tube + asbestos paper + M oxide before heating 47.95 gMass of combustion tube + asbestos paper + product after heating 44.75 g

    (i) Determine the empirical formula of M oxide.[Relative atomic mass of O=16, M=55]

    [3 marks]

    (ii) Write a chemical equation for the reduction of M oxide by hydrogen gas.

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

    (c) State one precaution that must be taken when carrying out the experiment.

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

    (d) Can the empirical formula of magnesium oxide be determined by the same method? Explain youranswer.

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

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

    [2 marks]

    Dry hydrogen gas

    M oxide

    Asbestos paper

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    5 Diagram 5 shows the set-up of apparatus for an experiment to determine the empirical formula of magnesiumoxide.

    Diagram 5

    Result:Mass of crucible + lid = 24.0 gMass of crucible + lid + magnesium ribbon = 26.4 gMass of crucible + lid + magnesium oxide = 28.0 g

    (a) What is meant by empirical formula?

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

    (b) Based on the above result,(i) calculate the mass of magnesium and the mass of oxygen that have reacted.

    [1 mark]

    (ii) calculate the mole ratio of magnesium atoms to oxygen atoms.[Relative Atomic Mass: O=16; Mg=24]

    [1 mark]

    (iii) determine the empirical formula of magnesium oxide.

    [1 mark]

    (iv) write the chemical equation for the reaction in the experiment.

    [1 mark](c) Why was the crucible lid opened once in a while during the experiment?

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

    (d) Metal X is placed below hydrogen in the reactivity series. You are required to carry out an experiment to

    determine the empirical formula of the oxide of metal X. The apparatus provided are combustion tube,glass tube, cork, Bunsen burner, and porcelain dish.(i) Draw a labelled diagram of of the apparatus set-up for the experiment.

    [2 marks]

    Magnesiumribbon

    Crucible

    Lid

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    (e) Describe the steps that should be taken to ensure that all the air in the combustion tube has beenexpelled.

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

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

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

    6 Diagram 6 shows the symbols for atom of element X, Y, and Z.

    Diagram 6

    (a) (i) Write the electron arrangement of atom X.

    ...[1 mark]

    (ii) State the period and the group for element X in the Periodic Table.

    Period : ...

    Group : ...........[2 marks]

    (b) (i) What is the proton number of element Z?

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

    (ii) Atom of element Y has a nucleon number of 35. Calculate the number of neutrons in atom Z.

    .[1 mark]

    (iii) Write the the standard representation of element Z

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

    (b) Element Y and Z are located in the same Group in the periodic table of element.Compare reactivity of element Y and Z. Explain your answer

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

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

    [4 marks]

    (c) Element X can react with sodium to form a compound

    (i)Name the type of bond in the compound formed between atoms X and sodium.

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

    Z

    X

    Y

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    (ii) Give one physical property of the compound in (c)(i).

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

    (d) Element X can also react with carbon to form a compound. Draw the electron arrangement for thecompound formed.[ Proton number of C = 11 ]

    [2 marks]

    7 Table 7 shows the proton numbers of elements X, Y and Z.

    Elements Proton Number

    X 12

    Y 8

    Z 6

    Table 7

    a) Write the electron arrangement for atom X

    [1 mark]

    b) X and Y react to form a compound

    i) What type of bond holds atom X and Y together?

    ...[1 mark]

    ii) What will happen to atom X during the formation of the compound with atom Y? Explain why.

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

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

    [2 marks]

    iii) Draw the electron arrangement of the compound formed in (b)(ii)

    [2 marks]

    iv) State one physical property of the compound formed

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

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    c) Z can react with Y to form a compound.

    i) What is the molecular formula of the compound formed?

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

    ii) What is the relative molecular mass of the compound in c(i).[ Given that relative atomic mass Z = 12; Y= 16]

    ..

    [1 mark]

    iii) Name another compound that has the same physical properties as thecompound formed.

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

    8 Diagram 8 shows the position of several elements P, Q, R, S, T, U and W.

    P

    Q T V U

    R S W X

    Diagram 8Using the symbols P, Q, R, S, T, U and W, answer the following questions.(a) State one metal and one non- metal

    Metal:..

    Non-metal:.

    [1 marks](b) Write the electron arrangement of atom V.

    ...[1 mark]

    (c) Which of the elements has the biggest atomic radius?

    .[1 mark]

    (d) (i) Compare the electronegativity of elements Q, T, V and U.

    ..[1 mark]

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

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

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

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

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

    [4marks]

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    (e) State the ion formed by Q.

    ....[1 mark]

    (f) (i) Which element is chemically inert?

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

    (ii) Explain your answer.

    ......[1 mark]

    (g) Write an equation for the reaction between R and U.

    .......[1 mark]

    (h) Give one special characteristic of S.

    ....[1 mark]

    9 Diagram 9 shows the chemical symbols which represent element P, Q, R and S.

    Diagram 9(a) (i) Write the electron arrangement of atom Q.

    ... [1 mark]

    (ii) State the period and the group for element Q in the Periodic Table.

    Period : ...

    Group : ............[2 marks]

    (b) Atoms of P and Q can react to form a compound.

    (i) Name the type of bond in the compound formed between atoms P and Q.

    [1 mark]

    (ii) Draw the electron arrangement for the compound formed.

    [2 mark](c) Atoms of R and S can also react to form a compound. Draw the electron arrangement for the compound

    formed.

    [ 2 marks]

    P23

    11 R14

    6 S35

    17Q16

    8

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    (d) Compare one physical property of compound formed (b) and (c). Explain your answer.

    [4 marks]

    10 Table 10 shows the melting point, boiling point and electrical conductivity of substances P, Q, R, and T .

    Electrical conductivitySubstance Melting point (

    oC) Boiling point (

    oC )

    Solid Molten

    P 805 1460 No Yes

    Q1549 2950 Yes Yes

    R-210 -153 No No

    T-7 59 No No

    Table 10(a) Which of the substances is a metal ?

    ..[1 mark]

    (b) (i) State the type of particle in substance P ?

    .[1 mark]

    (ii) Explain why substance P cannot conduct electricity in solid form but can conduct electricity inmolten state.

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

    .............................................................................................................................................................[2 marks]

    (c) (i) What is the physical state of R and T at room temperature ?

    R : ............................................

    T : ....... .................... .................

    [2 marks](ii) Draw the arrangement of particles in substance T at room temperature .

    [2 marks](iii) Explain why the melting and boiling points of substance R and T is low ?

    ..

    ..

    [2 mark]

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    [ 8 marks ]

    13. (a) Diagram 13.1 shows the standard representation for sodium element

    Diagram 13.1

    State three information that can be deduced from the diagramDraw the atomic structure of sodium atom .

    [6 marks]

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    (b) Diagram 13.2 shows the empirical formula of glucose :

    Diagram 13.1

    (i) What is the meaning of empirical formula ?(ii) The relative molecular mass of glucose is 180, determine the molecular

    formula of glucose[4 marks]

    (c) (i) A chloride of iron contains 2.80 g of iron and 5.32 g of chlorine.Determine the empirical formula of the compound.[ Relative atomic mass : Fe = 56 , Cl = 35.5 ]

    [4 marks](ii) Write a chemical equation to represent the reaction between iron and

    chlorine.Calculate the volume of chlorine gas that reacts completely with 2.80 g iron.[ 1 mole of gas occupied 24 dm

    3at room temperature and pressure ]

    [6 marks]

    14 (a) What is meant by empirical formula?[1 mark]

    (b) A carbon compound contains 92.3% of carbon and 7.7% of hydrogen by mass.The relative molecular mass of this compound is 78. Find the molecular formulaof this compound.

    [Relative atomic mass: C=12; H=1] [5 marks]

    (c) Describe how you could determine the empirical formula of magnesium oxidein the laboratory. Your description should include

    procedure of experiment

    tabulation of result

    calculation of the results obtained[Relative atomic mass: O=16; Mg=24] [11 marks]

    (d) Magnesium can reduce copper oxide to copper.

    Explain why the empirical formula of the copper oxide cannot be determined by heating the mixture ofcopper oxide and magnesium powder.

    [2 marks]

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    PAPER 2 ESSAY SECTION C

    15 (a) Diagram 15 shows the electron arrangement of a compound formed from the reaction betweenelement

    Y and element ZThese letters are not the actual symbols of the elements.

    Diagram 15

    (i) Based on diagram 15 , write the electron arrangement for atoms of element Y and Z.Explain the position of element Y in the Periodic Table of the Elements.

    [6 marks ](ii) Element Y can react with sodium and sodium hydroxide to form compounds.

    Write the chemical equation to represent the reaction .[4 marks ]

    (b) Table 15 shows the proton number for atoms P , Q and R.These letters are not the actual symbols of the elements.

    Table 15

    Using the information in table 15, explain how two compounds can be formed from these elements .The two compounds should have different bond types.

    [10 marks ]

    Elements Proton number

    P 11

    Q 17

    R 6

    Z Y

    +

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    PAPER 3 STRUCTURE16 An experiment is conducted to find out the freezing point of liquid naphthalene. A boiling tube

    containing molten naphthalene at 95 C is allowed to cool in a conical flask to room temperature. Thetemperature of naphthalene is recorded at half-minute intervals. Diagram 1 shows the reading of thethermometer for this experiment.

    Diagram 16

    (a) Record the temperature in the spaces provided in Diagram 16.[3 marks]

    (b) Construct a table to record the data shown in Diagram 16.

    [3 marks](c) (i) Draw a graph of temperature against time.

    [3 marks](ii) On your graph , mark the freezing point of naphthalene..

    [3 marks]

    90

    95

    85

    Initial temperature

    0 s :

    Temperature at

    30 s :

    85

    90

    80

    85

    90

    80

    85

    90

    80

    80

    85

    80

    85

    75

    80

    85

    75

    75

    85

    70

    Temperature at

    60 s :

    Temperature at

    90 s :

    Temperature at

    120 s :

    Temperature at

    150 s :

    Temperature at

    180 s :

    Temperature at

    210 s :

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    (d) (i) What is meant by freezing point ?

    [3 marks](ii) Explain why the temperature of naphthalene remains constant form 90

    thseconds to 150

    th

    seconds during the cooling process.

    .

    [3 marks](e) Why is the boiling tube placed in the conical flask during the cooling process ?

    .

    [3 marks]

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    (f) Diagram shows the arrangement of particles of four substances.

    Classify P, Q , R, and S into element and compound.

    Element Compound

    [ 3 marks ]

    17 A student carried out an experiment to determine the empirical formula of magnesium oxide. The stepand set-up of apparatus of the experiment are shown in Diagram 17.

    Step Set-up of apparatus

    1. Crucible and lid are weighed

    2. Crucible, lid and magnesium ribbon areweighed

    3. Magnesium and ribbons heated until thereaction is complete

    4. Crucible, lid and magnesium oxide areweighed when cold

    Diagram 17

    P Q R S

    Na Na NaNa

    Na Na NaNa

    Na Na NaNa

    Na

    Na+ Cl

    - Na

    +Cl

    -

    Cl-

    Na+

    Cl-

    Na+

    Na+ Cl

    - Na

    +Cl

    -

    Cl Cl

    Cl Cl

    Cl Cl

    Cl Cl

    O H

    O H

    O H

    O H

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    (a) Complete the following table by stating the observations and related inferences in the experiment.

    Observation Inferences

    (i)

    (ii)

    (i)

    (ii)

    [6 marks]

    (b) Record the reading to two decimal places forThe mass of crucible and lid :.g

    The mass of crucible, lid and magnesium ribbon: . g

    The mass of crucible, lid and magnesium oxide when cold: g

    [3 marks]

    (c) (i) What is the mass of magnesium that has been used?

    (ii) What is the mass of oxygen which reacted with magnesium?

    (iii) Determine the empirical formula of magnesium oxide.Use the information that the relative atomic mass, Mg = 24 and O = 16

    [3 marks]

    (d) Based on your answer in (c)(iii), how many moles of magnesium and oxygen atoms have reacted?

    [3 marks]

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    18

    An experiment is carried out to investigate the statement above. Table 18 shows the apparatus set upand the observations for the experiment to determine the reactivity of the Group 1 elements based ontheir reactions with water.

    Apparatus set-up Observation towards the metal

    Lithium moves slowly on the surface of the waterwith a hiss sound.

    Potassium moves vigorously and randomly on thesurface of the water with a hiss sound.

    Sodium moves quickly and randomly on thesurface of the water with a hiss sound.

    Table 18(a) State the variables that are involved in the experiment.

    Name of variables Action to be taken

    (i) 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 controlled variable:

    [6 marks]

    (b) State one hypothesis for the experiment.

    [3 marks]

    Elements in Group 1 of the Periodic Table of Elements can be arranged based on thereactivity of the elements with water.

    water

    water

    sodium

    Potassium

    water

    Lithium

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    When lithium metal is put into water, it moves very slowly on the surface of the water. When sodiummetal is put into water, it moves quite fast and produces hiss sound. When potassium metal is put

    into water, it moves very fast and produces small explosion.Metal

    (c) Based on the observations in the figure above, arrange lithium, potassium and sodium in thedescending order of reactivity of metals towards water.

    Descending order of reactivity of metals towards water.[3 marks]

    (d) Solution X was produced from the reaction of sodium with water. Classify the ions that exist in

    solution X into positive ions and negative ions.

    Positive Ions Negative Ions

    [3 marks]

    19

    Plan an experiment in the laboratory to investigate the reactivity of lithium, sodium and potassium with waterand describe the effect of the solution produced towards a red litmus paper.The planning of your experiment must consist of the following:

    (a) Aim of experiment(b) Statement of the hypothesis(c) All the variables(d) List of substances and apparatus(e) Procedure of the experiment(f) Tabulation of data

    [17 marks]

    Water

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    CHEMISTRY PERFECT SCORE MODULE

    SET

    1. Electrochemistry2. Oxidation and Reduction

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    1 Diagram 1 shows the set-up of apparatus to investigate the electrolysis of 1.0 mol dm-3

    of sodium sulphatesolution using carbon electrodes.

    (a) i) What is meant by anion?

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

    ii) State all the anions present in the electrolyte.

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

    (b) What is the energy change that occurs in the above process?

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

    (c) Write the formulae of the ions which move to the electrode X.

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

    (d) i) State the name of the gas collected in the test tube at the electrode X

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

    [1 mark]ii) Write the half equation for the reaction at the electrode X

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

    iii) Describe the chemical test to confirm the gas in (d) (i) .

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

    ...........................................................................................................................................................[2 marks]

    (e) If the sodium sulphate solution is replaced by the copper(II) sulphate solution in the aboveelectrolysis,

    i) what is the observation at the electrode X

    ....[1 mark]

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

    .....

    ..[2 marks]

    Carbon electrode X

    sodium sulphate 1.0 mol dm-

    solution

    A

    Diagram 1

    Carbon electrode Y

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    2 Diagram 2 shows the set up of apparatus of a chemical cell.

    (a) Mark the direction of the flow of electrons in the above diagram. [1 mark]

    (b) (i) What is the function of the salt bridge?

    ...[1 mark]

    (ii) Suggest a suitable chemical substance to be used as salt bridge.

    ...[1 mark]

    (c) State the energy change in the cell above.

    ..[1 mark]

    (d) i) State the negative terminal

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

    ii) Explain your answer in d(i).

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

    (e) i) State one observation at the copper electrode.

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

    ii) Write the half equation for the reaction in (e) (i).

    .......[1 mark]

    (f) i) Voltage value of the cell is 2.7 V. If the magnesium is replaced by zinc, predict the voltage valueproduced.

    ......

    [1 mark]ii) Explain your answer.

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

    .. [1 mark]

    Diagram 2

    Salt bridge

    Copper

    Magnesiumnitrate solution

    Magnesium

    Copper(II) nitratesolution

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    3 Diagram3shows the set-up of the apparatus to study the reactions that take place in test tubes X and Y.

    Diagram 3

    (a) State the observation for the reaction

    i) in the test tube X

    ...[1 mark]

    ii) in the test tube Y

    ..[1 mark]

    (b) Write the ionic equation for the reaction in (a)(ii)

    ...[2 marks]

    (c) State what is meant by an oxidising agent in terms of electron transfer.

    ..[1 mark]

    (d) Referring to the reaction that takes place in the test tube X,

    i) what is the change in the oxidation number of bromine ?

    .[1 mark]

    ii) state the name of the reducing agent.

    ...[1 mark]

    (e) Referring to the reaction that takes place in test tube Y,

    i) state the substance that is oxidised.

    ..

    [1 mark]ii) write the half equation to represent the reaction that occurred in (e)(i).

    .[1mark]

    iii) what is function of chlorine water?

    ....[1 mark]

    iv) State the name of another reagent that can replace chlorine water.

    ..[1 mark]

    Iron (II)sulphatesolution

    Brominewater

    Sodium bromidesolution

    Chlorinewater

    X Y

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    4 Table 4 shows the observation of an experiment to study the reactivity of metals X , Y and Z withoxygen. Metal powders of X , Y and Z are heated vigorously in a flow of oxygen. Potassiummanganate(VII) powder is used as the source of oxygen.

    ObservationMetal powderand colour While heating after heating

    X Brown Glows faintly Black powder

    Y Grey Burns vigorously with bright flame White powder

    Z Grey

    Burns fairly bright

    Yellow powder White powder

    Table 4

    (a) State the name ofone compound that can be used to substitute potassium manganate(VII) in thisexperiment.

    .[1 mark]

    (b) (i) State the type of reaction undergone by the metal powders?

    [1 mark]

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

    ...[1 mark]

    (c) Suggest the name of metal Z.

    ..[1mark]

    (d) Based on the observation in table 1 , arrange the reactivity of metal X , Y and Z in ascending order.

    .[1 mark]

    (e) Draw a labelled diagram of the set-up of apparatus for this experiment.

    [2 marks](f) 4.8 g of metal Y reacts with oxygen to produce 8.0 g of oxide Y.

    Calculate the empirical formula of oxide Y.[Relative atomic mass: O=16 ; Y = 24]

    [3 marks]

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    Essay (Section B)

    5 (a) Copper (II) sulphate solution is electrolysed using carbon electrodes.What is produced at the cathode. Write a half equation for the reaction occurred .

    [2 marks]

    (b) Diagram 5 shows the set-up of apparatus to study whether substance X is an electrolyteor non- electrolyte .

    DIAGRAM 5

    Table 5.1 shows substance X and their observation .

    Substance X Observation

    Solid sodium chloride Bulb does not light up

    Sodium chloride aqueous solution Bulb lights up

    Solid naphthalene Bulb does not light up

    Table 5.1

    (i) Explain the observation for each substance. [6 marks]

    (ii) Classify substance X into electrolyte and non-electrolyte.

    [1 mark]

    (b) Concentration of electrolyte affects the product of electrolysis at the electrode.By using sodium chloride solution, explain briefly how to prove that statement. In yourexplanation, write the chemical equation involved.

    [6 marks]

    (c) Table 5.2 shows the result of experiment for displacement reaction between substance P, Qand R with salt solution of P, salt solution of Q and salt solution of R.

    Salt solution of P Salt solution of Q Salt solution of R

    P - Q X -

    R X X -

    : reaction occur

    X : No change

    Table 5.2

    Arrange metal P, Q and R in ascending order of electropositivity. Explain your answer.[4 marks]

    Substance X

    Carbon electrode

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    6 Table 6 shows the observation of two experiment to study the effect of metal P and metalQ on the rusting of iron. Rusting of iron is a redox reaction.

    Experiment After 1 day Observation

    I Large amount of darkblue precipitate

    II No dark blue precipitate.Solution turns pink.

    Table 6

    (a) By using a chemical equation , explain what is meant by redox reaction in term of electrontransfer.

    [3 marks]

    (b) Explain why there is a difference in observation in experiment I and experiment II. Arrange indescending order metals P, iron and Q based on the electropositivity of the metals.

    [8 marks]

    (c) With the aid of a suitable diagram, describe the rusting process of iron.[7 marks]

    (d) Explain why the rusting of iron at coastal area is faster.[2 marks]

    Essay (Section C)

    7 a) Explain why potassium iodide can conduct electricity in the molten state but cannot do so in thesolid state.

    [2 marks]b) Diagram 7 shows two types of cells.

    Compare and contrast cells A and B. Include in your answer the observations and half equations forthe reactions at the electrodes in both cells.

    [8 marks]

    Silverelectrodes Zinc

    electrode

    Silverelectrode

    Silver nitratesolution

    Cell A Cell B

    Diagram 7

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    The electric current is produced by the transfer of electron at a distance from a

    reducing agent to an oxidizing agent in a chemical reaction

    c) A student intends to purify an impure copper plate. Design an experiment to purify the copper plat.Your answer should consist of the following:

    Chemical required

    Procedures of the experiment

    Labelled diagram showing the set up of apparatus

    Half equation involved in the reaction

    Observations[10 marks]

    8 (a) 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]

    (b) By using a suitable example and the chemical equation, explain why the neutralization reaction isnot a redox reaction. [4 marks]

    (c) Table 8 shows some examples of oxidizing agents and reducing agents.

    Oxidising agent Reducing agent

    Acidify potassium manganat(VII) solution,KMnO4

    Iron(II) Sulphate solution,FeSO4

    Acidify potassium dichromate(VI) solution,K2Cr2O7

    Potassium iodide solution,KI

    Chlorine waterCl2

    Potassium bromideKBr

    Bromine waterBr2

    Hydrogen peroxideH2O2

    Table 8

    By using any oxidizing agent and reducing agent given, describe an experiment to prove thestatement above.

    Your description must include the following;

    o set up of the apparatus

    o procedure of the experimento observationso ionic equations

    [10 marks]

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    Paper 3

    9 Diagram 9 shows the set-up of apparatus for an experiment to construct the electrochemical series bymeasuring the potential difference produced by a simple voltaic cell.

    Diagram 9

    The experiment is repeated by substituting metal P with Q and R. Diagram 9 shows the reading of thevoltmeter when different pairs of metals are used. For each of the voltaic cell, copper acts as a positiveterminal.

    Diagram 9

    a) State the potential difference and the negative terminal by completing Table 9

    Metal pairs Potentialdifference / V

    Negative terminal

    Copper/ Metal P

    Copper/ Metal Q

    Copper/ Metal R

    [3 marks] Table 9

    (b) State the hypothesis of the experiment.

    [3 marks]

    Copper

    1.5

    V

    1.0

    0.5

    0

    2.5

    3.0

    2.0

    Copper / Q

    1.5

    V

    1.0

    0.5

    0

    2.5

    3.0

    2.0

    Copper / R

    Copper / P

    1.5

    V

    1.0

    0.5

    0

    2.5

    3.0

    2.0

    Metal P

    Copper(II) sulphate 1.0 mol dm-3

    solution

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    (c) Based on the experiment, complete the following table:

    Manipulated variable:

    ...

    Method to manipulate the variable:

    ..

    ..

    ..

    Responding variable:

    How the variable is responding:

    ..

    ...

    ..

    Controlled variable:

    .

    Method to maintain the controlled variable:

    [6 marks]

    (d) Based on Table 5, arrange copper, metal P, Q and R according to the descending order ofelectropositivity.

    .. ..[3 marks]

    10 A student carries out an experiment to investigate the oxidation and reduction in electrolytic cell.Copper(II) sulphate solution is electrolysed using copper electrodes for 30 minutes.

    Diagram 10 shows the set-up of apparatus for the electrolysis of copper(II) sulphate solution using

    copper electrodes.

    Beginning of experiment After 30 minutes

    Diagram 10

    A

    Copper electrodes

    Copper(II) sulphatesolution

    Bluesolution

    Bluesolution

    A

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    (a) Write the observations at the anode ,cathode and copper(II)sulphate solution..

    Observations

    Anode

    Cathode

    Copper(II)sulphatesolution

    [3 marks]

    (b) Based on the observations , what inferences can be made?

    Inference

    Anode

    Cathode

    Copper(II)sulphatesolution

    [3 marks]

    (c) Write the half-equation to represent the oxidation and reduction that occurres at cathode andanode.

    Oxidation : ....................................................................................................................................

    Reduction : ...................................................................................................................................

    [3 marks]

    (d) State the operational definition for the reaction that takes place at the anode

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

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

    (e) Predict the product formed at anode, if copper electrode in this experiment isreplaced with carbon electrode.

    ...

    ...[3 marks]

    (f) Classify all positive and negative ions that are found in the copper(II) sulphate solution..

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

    .

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

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    Metal X is more electropositive than iron.

    Metal Y is less electropositive than iron.

    11

    You are given the copper strip, lead strip, iron strip, zinc strip, aluminium strip, and magnesium strip .By referring to the statement above, plan a laboratory experiment to construct the electrochemicalseries of the potential differences using different pair of metals.

    Your explanation should include all the followings:

    (a) Aim of the experment(b) All the variables(c) Statement of the hypothesis(d) List of materials and apparatus(e) Procedure of the experiment(f) Tabulation of data [17 marks]

    12

    Referring to the above statements, plan a laboratory experiment to investigate the effect of rusting ofiron when in contact with metal X and metal Y.

    Your planning should include the following aspects:

    (a) Problem statement

    (b) All the variables

    (c) Hypothesis

    (d) List of materials and apparatus

    (e) Experimental procedure

    (f) Tabulation of data

    [17 marks]

    The further the distance between two metals in the

    electrochemical series, the bigger is the potential difference.

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    CHEMISTRY PERFECT SCORE MODULE

    SET

    1. Acids and Bases2. Salts3. Rate od reaction4. Thermochemistry

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    1 An experiment is carried out to investigate neutralization reaction between 1.0 moldm-3

    of sulphuric acidand 25 cm

    3of sodium hydroxide. A few drops of phenolphthalein are added to the solution. The acid is

    added slowly to the flask until end point. The result of the experiment is shown in table 1.

    1 2 3

    Initial reading of burette ( cm3

    ) 17.30 17.00 17.70

    Final reading of burette ( cm3

    ) 39.70 39.20 39.70

    Volume of acid used ( cm3

    )

    Table 1

    a) What is meant by end point?

    ...

    [1 mark]

    b) State the change of colour of phenolphthalein during titration.

    ..

    [1 mark]

    c) Fill in the table by calculating the volume of sulphuric acid used in the experiment.[1 mark]

    d) Write chemical equation of the reaction in this experiment.

    .

    [1 mark]

    e) (i) Calculate the average volume of sulphuric acid used in the reaction.

    [1 mark]

    (ii) Calculate the number of mol sulphuric acid used in the reaction

    [1 mark]

    f) Draw a labeled diagram to show the set up of apparatus used in the experiment.

    [2 marks]

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    g) State two precautions that should be taken during the experiment

    .

    ...

    [2 marks]

    2 An experiment is carried out to determine the concentration of sulphuric acid by titration. A few drops of

    methyl orange indicator is added to 20.00 cm3 of 0.1 mol dm3 potassium hydroxide solution in a conicalflask. Sulphuric acid of unknown concentration is then added. The results obtained are shown in thetable 2.

    Titration I II III IV V

    Volume of acid added / cm3 5.00 10.00 15.00 20.00 25.00

    Colour of the mixture Yellow Orange Red

    Table 2(a) What is the colour of methyl orange

    (i) in an acidic solution?

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

    (ii) in an alkaline solution?

    [1 mark]

    (iii) in a neutral solution?

    ...[1 mark]

    (b) What is the volume of sulphuric acid that completely neutralises 20.00 cm3

    of 0.1 mol dm3

    sodiumhydroxide solution?

    ..[1 mark]

    (c) Write

    (i) a chemical equation for the reaction.

    ...[1 mark]

    (ii) an ionic equation for the reaction.

    ..[1 mark]

    (d) Calculate the molarity of sulphuric acid.

    [1mark]

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    (e) What is the colour of the mixture when a total of(i) 5.00 cm

    3of acid is added?

    [1 mark]

    (ii) 25.00 cm3

    of acid is added?

    .....[1 mark]

    (f) What is the expected volume of 0.1 moldm-3

    hydrochloric acid that neutralises completely 20 cm3

    of

    0.1 mol dm3

    potassium hydroxide solution?

    ....[1 mark]

    3 Diagram 3 below shows laboratory activities in preparation of a salt.

    Diagram 3

    (a) Name the type of reaction in the preparation of salt.

    ....[1 mark]

    (b) Explain why zinc carbonate powder is added in excess.

    .....

    [1 mark](c) Write a chemical equation for the reaction that occurs inside the beaker.

    ....[1 mark]

    (d) Draw the apparatus set-up used to separate the excess zinc carbonate powder from the mixture inthe diagram above.

    [2 marks](e) Calculate the maximum mass of the salt formed.[Relative atomic mass: N=14, O=16, Zn=65]

    [2 marks]

    50 cm3of

    2 mol dm-3

    nitric acid

    Excess zinc oxide powder

    Heat Heat

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    (f) Suggest two substances that can replace zinc oxide in the experiment to obtain the same type of salt.

    .[2 marks]

    4 6.0 cm3of 0.5 mol dm

    -3silver nitrate solution is poured into 6 different test tubes. Different volume of 1.0

    mol dm-3

    sodium chloride solution are added to each test tube. The mixture is shaken and the height ofprecipitate formed in each test tube is measured and recorded as shown in the table 4.

    Table 4

    (a) State the name of the precipitate formed.

    ...[1 mark]

    (b) What is the colour of the precipitate?

    ...[1 mark]

    (c) What is the volume of sodium chloride needed to completely react with 6.0 cm3

    silver nitrate solution?

    ....

    [1 mark](d) Calculate

    (i) the number of moles of silver nitrate in the reaction.

    [1 mark](ii) the number of moles of sodium chloride that has completely reacted with 1 mole of silver

    nitrate.

    [2 marks]

    (e) Write the ionic equation for the formation of the precipitate.

    ...[1 mark]

    (f) Predict the height of the precipitate formed in test tube 6.

    ..

    [1 mark]

    Test tube 1 2 3 4 5 6

    Volume of 0.5 mol dm-3

    silver

    nitrate solution (cm3

    )6.0 6.0 6.0 6.0 6.0 6.0

    Volume of 1.0 mol dm-3

    sodium chloride solution (cm3)

    1.0 2.0 3.0 4.0 5.0 6.0

    Height of precipitate (cm) 0.5 1.0 1.5 1.5 1.5 ..

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    (g) The concentration of sodium chloride solution is changed from 1.0 mol dm-3

    to 2.0 mol dm-3

    and theother conditions remain the same. Sketch the graph of height of precipitate against the volume ofsodium chloride solution.

    [2 marks]

    4 Diagram 5 shows a series of reactions for copper(II) oxide and its other compounds.

    Diagram 5

    (a)(i) Name the solution W.

    ...[1 mark]

    (ii) Describe briefly how to prepare a sample of dry salt from solution W.

    ..

    .

    ..

    ...[3 marks]

    (b)(i) What do you observe when dilute sodium hydroxide solution isadded drop by drop until in excess into solution W?

    .....

    ......[2 marks]

    (ii) Write down the formula of precipitate X.

    .[1 mark]

    Copper(II)oxide

    SolutionW

    Precipitate Y

    Precipitate X Dark bluesolution

    Solution ZDilute sodiumhydroxide solution

    Lead(II) nitratesolution

    heat

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    (c) Solution Z is added into solution W until no changes are observed. A dark blue solutionis formed. Name the solution Z.

    .[1 mark]

    (d) When solution W is added into lead(II) nitrate solution in a test tube, precipitate Y andcopper(II) nitrate solution are formed.(i) What is the colour of precipitate Y?

    .[1 mark]

    (ii) Write down the ionic equation to show the formation of precipitate Y.

    ....[1 mark]

    (iii) How can you separate precipitate Y from copper(II) nitrate solution?

    ...[1 mark]

    6 An experiment was conducted to study the effect of temperature on the rate of reaction between 50 cm3

    of sodium thiosulphate solution 0.2 mol dm-3

    and 5 cm3

    of sulphuric acid 1.0 mol dm-3

    to form a yellowprecipitate. Diagram 6 shows the set-up of apparatus for the experiment.

    Diagram 6

    The experiment was repeated five times using different temperatures. Table 1 shows the temperatureand time taken for mark X to disappear from view.

    Experiment Temperature/oC Time/s

    1 28.0 55

    2 40.0 33

    3 50.0 23

    4 60.0 17

    5 70.0 13

    Table 1

    (a) Draw a graph of temperature against time for this experiment. [3 marks]

    (b) From the graph, calculate the rate of reaction in(i) Experiment 2

    (ii) Experiment 4

    [2 marks]

    50 cm3

    of sodium thiosulphatesolution 0.2 mol dm

    -3+ 5 cm

    3of

    sulphuric acid 1 mol dm-3

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    (c) Compare the rate of reaction between Experiment 2 and Experiment 4.Explain your answer by using the Collision Theory.

    .

    .

    .

    .

    ..[5 marks]

    (d) Write the chemical equation for the reaction.

    .[1 mark]

    (e) Name the yellow precipitate formed.

    ..[1 mark]

    (f) State one other factor that can affect the rate of reaction for this experiment.

    ...[1 mark]

    7 Three experiments were conducted to study the rate of reaction between hydrochloric acid and zinc.Table 7 shows the the mixture of the substances used and time taken to collect 25 cm

    3of gas released

    in each experiment.

    Expeiment Mixture of substances used Time/s

    I20.0 cm

    3hydrochloric acid 1.0 mol dm

    -3+

    2.0 g zinc50.0

    II20.0 cm

    3hydrochloric acid 1.0 mol dm

    -3+

    2.0 g zinc + 5 drops of copper(II) sulphatesolution

    32.0

    III20.0 cm

    3sulphuric acid1.0 mol dm

    -3+

    2.0 g zinc25.0

    Table 7

    (a) Draw the set-up of apparatus used in this experiment.

    [2 marks](b) Calculate the average rate of reaction in Experiment II.

    [1 mark](c) Write the ionic equation for the reaction.

    ...[1 mark]

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    (d) Compare the rate of reaction between Experiment I and II.Explain your answer by using the Collision Theory.

    ...

    ...

    ...

    ...[4 marks]

    (e) Compare the rate of reaction between Experiment I and III.Explain your answer by using the Collision Theory.

    ..

    ...

    .

    .[4 marks]

    (f) (i) State the name of the gas collected in the experiments.

    ...

    [1 mark](ii) Describe one test to confirm the gas collected in (f)(i).

    ..

    ..[2 marks]

    8 An experiment is carried out to determine heat of displacement for the reaction between copper andsilver nitrate solution. In this experiment, excess copper powder is added to 50 cm

    3of silver nitrate

    solution 0.5 mol dm-3

    . The heat of displacement in this experiment was -105 kJ mol-1

    .Specific heat capacity of the solution is 4.2 J g

    -10C

    -1

    (a) What is meant by heat of displacement ?

    .[1 mark](b) State another observation besides the change in temperature.

    .....[1mark]

    (c) Based on the information from this experiment, calculate(i) the number of moles of silver ions reacted.

    [1 mark]

    (ii) the amount of heat released.

    [1 mark](iii) the change in temperature.

    [2 marks]

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    (d) State two assumptions made during the calculations.

    ..

    ..[2 marks]

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

    [2 marks]

    (f) Polystyrene cup A is used in the above experiment . The experiment is repeated using cup B.Predict the change in temperature. Explain your answer.

    Prediction:

    ..[1 mark]

    Explanation:

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

    ............................[2 marks]

    (g) Explain why copper powder used in this experiment is in excess.

    ............................[1 marks]

    (h) If copper powder is replaced with magnesium, predict the change of the magnitude in heat ofreaction obtained. Explain your answer.

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

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

    [2 marks]

    Cup A

    Polystyrenecup

    Cup B

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    9 Experiment I is carried out to determine the heat of neutralisation between strong acid and strong alkali. It isfound that the heat of neutralisation is 57 kJ mol

    -1. The diagram 9 show the energy level diagram for the

    reaction between strong acid and strong alkali.

    Diagram 9

    a) Name an example of strong acid and a strong alkali.

    .[1 mark]

    b) What is meant by heat of neutralisation in the experiment?

    .

    .[1 mark]

    c) State two information about the reaction which can be obtained from the above energy level diagram.

    .

    .

    .[2 marks]

    d) In another experiment, experiment II is carried under the same conditions as experiment I, whereby a50 cm

    3of 1 mol dm

    -3ethanoic acid is added to 50 cm

    3of strong alkali with a concentration of 1 mol

    dm-3.

    The temperature of the mixture increased by 6.50C.

    (i) Calculate the number of moles of strong alkali used.

    [1 mark](ii) Calculate the heat of neutralization for the reaction between ethanoic acid and strong alkali

    [Specific capacity for all solutions is 4.2 Jg-1o

    C-1

    and the density of all solutions is 1.0 g cm-3

    ]

    [3 marks]

    Energy

    H2O(l)

    H

    +

    (aq) + OH

    -

    (aq)

    H = -57 kJ mol-

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    e) (i) Compare the heat of neutralization for Experiment I and Experiment II

    [1 mark]

    (ii) Explain your answer in e(i)

    ..[2 marks]

    f) If Experiment II is repeated by adding 100 cm3

    of 1 mol dm-3

    ethanoic acid to 100 cm3

    strong alkaliwith concentration 1 mol dm

    -3, the increase in temperature is still 6.5

    0C. Explain why.

    .

    ..[2 marks]

    ESSAY SECTION B

    10 (a) What is meant by strong acid?[2 marks]

    (b) Two samples of acids are tested and exhibit the same pH value. One sample is 50 cm3

    0.5 moldm-3

    of suphuric acid while another sample is 50 cm

    31.0 moldm

    -3of hydrochloric acid. Explain why.

    [4 marks]

    (c)Diagram 10 shows hydrogen chloride gas being prepared in the laboratory by adding concentratedsulphuric acid slowly through a thistle funnel to solid sodium chloride. The gas produce is passedthorough water and methylbenzene

    Diagram 10(i) State the observations when aqueous hydrogen chloride solution and hydrogen chloride in

    methylbenzene are added with the following:- Universal Indicator- Zinc powder- Copper(II) oxide powder

    [6 marks]

    (ii) Based on your answer in c(i), which of the solution is acidic? Explain your answer.[4 marks]

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    (iii) Diagram 10 shows the apparatus used to study whether aqueous hydrogen chloride solution andhydrogen chloride in methylbenzene are an electrolyte or non- electrolyte .

    Experiment I Experiment II

    Diagram 10

    State the observations in experiment I and II. Explain your answer.

    [4 marks]

    11 (a) You are required to prepare a dry sodium nitrate salt. The chemicals supplied are:

    Dilute nitric acid

    Sodium hydroxide solution

    Phenolphthalein

    Describe a laboratory activity to prepare the salt. Your answer should include the chemicalequation involved.

    [10 marks]

    (b) Decribe briefly how you prepare copper(II) chloride salt solution from the chemical substancesprovided below.

    Copper(II) sulphate solution

    Dilute hydrochloric acid

    Sodium carbonate solution

    [6 marks](c) Potassium carbonate solution is added into lead(II) nitrate solution to produce solid X and

    potassium nitrate solution. The mixture is shaken, then filtered. Solid X is heated to produce solid Pand gas Q.(i) Name solid P and state its colour. [2 marks](ii) Name gas Q and describe a method to verify its identity. [2 marks]

    ESSAY SECTION C12 (a) Using suitable examples, explain what is meant by

    (i) diprotic acid(ii) strong acid

    [4 marks](b) 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 solidpotassium hydroxide .Describe how you would prepare 250 cm

    3of 0.1 mol dm

    -3potassium hydroxide from the solution.

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

    A

    Carbonelectrode

    aqueous hydrogenchloride solution

    A

    Carbonelectrode

    hydrogen chloridein methylbenzene

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    [10 marks]

    13 (a) An insoluble salt can be prepared by the precipitation reaction.Give an example of an insoluble salt and suggest two solutions to prepare the insoluble salt.Write the ionic equation to represent the precipitation reaction.

    [4marks]

    (b) Figure below shows an incomplete flow chart of cation and anion tests for salt X.

    Use the reagents listed below to confirm that salt solution of X contains Fe2+

    ions and SO42-

    ions.

    [6marks]

    (c) Magnesium sulphate is soluble salt. Describe how to prepare a dry sample of magnesium sulphate in thelaboratory.

    Your answer should consist of the following:

    Chemicals required

    Procedure of the preparation

    Chemical equation involved in the reaction [10marks]

    14 (a) Zn(s) + CuSO4(aq) ZnSO4(aq) + Cu(s) H = - 152 kJmol-1

    (i)

    (ii)

    Draw an energy level diagram for the above equation.[2 marks]

    Explain the differences in energy content of reactants as compared to the products.

    [2 marks](b) Table below shows the result of neutralization reactions.

    Experiment Neutralization reaction Heat release (kJ)

    I NaOH + HCl NaCl + H2O 57

    II NaOH + CH3COOH CH3COONa + H2O 54

    III 2NaOH + H2SO4 Na2SO4 + 2H2O 114

    Explain why there are differences in heat released between;

    (i)

    (ii)

    Experiment I and Experiment II[3 marks]

    Experiment I and Experiment III[3 marks]

    REAGENTS

    Sodium hydroxide solution Ammonia solution

    Hydrochloric acid

    Barium chloride solution

    SO42-

    Fe2+

    Cation test Anion test

    Salt solutionof X

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    (c)

    Describe a laboratory experiment to determine the heat of reaction for the above reaction,include the following in your answer:[Relative atomic mass : C=12 ; O=16 : H=1 ]

    o diagram showing the set-up of apparatuso chemicals requireso procedures of the experiment

    o a table to collect the datao calculation involved

    [10 marks]

    15 (a) What is the meaning of the heat combustion of propanol?[2 marks]

    (b) (i) By using a labeled diagram describe an experiment how to determine the heat ofcombustion of the propanol in the laboratory.In your explanation, state together the necessary steps to calculate the heat of combustion ofpropanol. [Relative molecular mass of propanol = 60]

    [14 marks](ii) State the precaution steps that should be taken during this experiment.

    [2 marks]

    (c) Table 15 shows the value of the heat of combustion for methanol and propanol.

    Alcohol compounds Heat of combustion/kJ mol-1

    MethanolPropanol

    -723-2004

    Table 15

    Compare the heat of combustion of methanol (CH3OH) with the heat of combustion of propanol(C3H7OH). Explain your answer.

    [2 marks]

    PAPER 3

    16 Two experiments are carried out to study the effect of the size of calcium carbonate on the rate ofreaction.Experiment I: 1 g of calcium carbonate chips react with 20.0 cm

    3of 0.2 mol dm

    -3hydrochloric acid

    Experiment II: 1 g of calcium carbonate powder react with 20.0 cm3

    of 0.2 mol dm-3

    hydrochloric acidThe rate of reaction is determined by measuring the volume of of carbon dioxide gas given off againsttime using the downward displacement of water method.The volume of gas released is recorded in Table 17.1 and Table 17.2 below.Experiment I

    Time / s0 60 120 180 240 300 360

    Burette reading / cm3

    50.00 18.00 9.50 8.00 8.00

    Volume of gas / cm3

    0.00

    Table 16.1Experiment II

    Time / s 0 60 120 180 240 300 360

    Burette reading / cm3

    50.00 22.00 13.50 9.00 8.00 8.00 8.00

    Volume of gas / cm3

    0.00

    Ca2+

    (aq) + CO32-

    (aq) CaCO3 (s) H = + 12.6 kJmol-1

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    Table 16.2

    Diagram below shows the burette reading for Experiment I at 60, 120 and 180 seconds.

    (a) Record the burette reading and the volume of gas released at 60, 120 and 180 seconds in Table16.1.

    [3 marks](b) Record the volume of gas released in both experiments in Table 16.1 and Table 16.2.

    [3 marks](c) By using the same axes, draw a graph of the volume of gas released against time for Experiment

    I and II. [3 marks](d) Based on the graph in (c), which experiment has a higher rate of reaction? Explain your answer.

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

    (e) (i) State the variables involved in this experiment.Manipulated variable

    Responding variable

    .

    Constant variable

    .[3 marks]

    (ii) State the hypothesis for these experiments.

    .........

    . .......

    ..[3 marks]

    (f) Predict the volume of gas released at 420 seconds in Experiment II.

    .....[3 marks]

    (g) Classify the following reaction into fast reaction and slow reaction.

    [3 marks]

    17 A student perform an experiment to determine the heat displacement of copper. 50 cm3

    ofcopper (ll)

    sulphate solution 0.5 mol dm3was poured into a polystyrene cup. Initial temperature of the solution

    Burette reading at 60 seconds

    25

    24

    23

    Rusting, Fermentation, Neutralization, Photosynthesis, Combustion, PrecipitationCombustion, Corrosion, Displacement

    Burette reading at 120 seconds

    19

    18

    17

    Burette reading at 180 seconds

    14

    13

    12

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    was recorded. Then excess zinc powder was added into the copper(II) sulphate solution in thepolystyrene cup and stirred as shown in diagram 18.1.

    Before AfterDiagram 17.1

    The initial temperature and maximum temperature were recorded as in diagram 17.2

    Initial temperature maximum temperatureDiagram 17.2

    (a) State two observations in this experiment

    .

    .[3 marks]

    (b) Refer diagram 17.2, determine the temperature value

    Initial temperature.

    Maximum temperature .

    Temperature difference .[3 marks]

    (c) Calculate the heat change in this experiment.(Heat capacity of solution = 4.2 g

    -1 0C

    -1,Density of solution = 1 gcm

    -3)

    [3 marks]

    (d) Give the inference for this reaction

    .

    .

    .[3 marks]

    (e) In another experiment , excess zinc powder was poured into 50 cm3

    copper(I l) sulphate solution1mol dm

    3. Predict the change in temperature obtained in this experiment.

    [3 marks]

    30

    --

    --

    25

    40

    --

    --

    35

    Zinc powder

    Polystyrenecup

    Copper(II) sulphatesolution

    thermometer

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    (f) Write ionic equation for the reaction in this experiment

    ....[3 marks]

    Essay Paper 3

    19

    Design a laboratory experiment to compare the heat of combustion for the above mentioned fuels.Your answer should include the following:(a) Aim of experiment(b) Hypothesis(c) All variables(d) List of materials and apparatus(e) Procedure(f) Tabulation of data

    [17 marks]

    CHEMISTRY PERFECT SCORE MODULE

    A company manager was approached by a sales man who tried to convince him octane(petrol) is a better fuel than heptane in terms of the heat released when burnt in excessoxygen .

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    SET

    1. Carbon Compounds2. Manufactured Substances in

    Industry3. Chemicals for Consumers

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    1. Table 1 below shows molecular formulae of four carbon compounds.

    Compound Molecular Formula

    S C3H6

    T C4H10

    U C3H7OH

    V C2H5COOH

    Table 1

    (a) Write the general formula of the homologous series of compound T.

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

    (b) State the functional group of compound S and compound V

    Compound S :....

    Compound V : .[2 marks]

    (c) Compound T shows isomerism. Draw the structural formula ofall isomers of compound T and give

    the IUPAC name.

    [4 marks]

    (d) Compound V and compound U are reacted with the presence of the concentrated sulphuric acid.

    (i) State the name of the product formed from the reaction.

    .....

    (ii) State the uses of concentrated sulphuric acid.

    ....(iii) State the special characteristic of the product

    ..[3 marks]

    (e) Compound U burns in excess oxygen to produce carbon dioxide and water.(i) Write a balanced chemical equation for the reaction.

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

    [1 mark](ii) 11.2 g of compound U burns in excess oxygen, calculate number of carbon dioxidemolecules formed.[Relative atomic mass C = 12, O = 16 and Avogadro number = 6.03 x 10

    23]

    [2 marks]

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    2 Diagram 2 shows a series of conversions that involves an alcohol, P which has a molecular formula of

    C2H 5 OH.

    Diagram 2

    (a) Draw the structural formulae of P and Q.

    P: Q:

    [2 marks]

    (b) State the name of the substance required for Process I

    ..[1 mark]

    (c) State one observation if an aqueous solution of Q is added to sodium carbonate solution.

    ..[1 mark]

    (d) P can react with Q to form an organic compound.(i) Write the chemical equation for the reaction

    .(ii) State the name of the compound formed

    [2 marks]

    (e) (i) State the name of Process I.

    (iii) Write the chemical equation for this reaction

    ..[2 marks]

    (f) Alcohol, P can be obtained from glucose.(i) State the name of the process involved.

    .

    (iii) Write the chemical equation for this process

    .[2 marks]

    Alcohol, PC2H5OHHydrocarbon, R

    Carboxylic acid, QCH3COOH

    Process IProcess II

    GlucoseC6H12O6

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    3. Diagram 3 shows the structure of olive oil.

    H

    H C OOC(CH2)7CHCH(CH2)7CH3

    H C OOC(CH2)7CHCH(CH2)7CH3

    H C OOC(CH2)7CHCH(CH2)7CH3

    H

    (a) (i) State the name ofthe homologous series that olive oil belongs to.

    [1 mark]

    (ii) Circle on the diagram, the functional group that determines the homologous series forolive oil.

    [1 mark]

    (iii) Write down the formulae of the two main components to make olive oil

    [2 marks]

    (b) Is olive oil a saturated or unsaturated compound? Give a reason.

    [2 marks]

    (c) Olive oil can be converted into margarine.(i) Name the reactant, catalyst and temperature for the reaction to convert olive oil to

    margarine.

    Reactant:..

    Catalyst:

    Temperature:..

    (ii) Name the type of reaction in c(i).

    [4 marks]

    Diagram 3

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    4. Diagram 4 shows the conversions of organic compound A to another substances, C2H4Br2and C2H5OH through Processes A and C.

    (a) What is meant by organic compound?

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

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

    (b) (i) Write the molecular formula of compound A.

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

    (ii) State the name of the compound A.

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

    (iii) Identify a functional group of compound A.

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

    (c) Compound A reacts with Reagent B to produce substance C2H4Br2 through Process I.

    (i) Suggest Reagent B.

    ...............................[1 mark](ii) State the name of Process I.

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

    (iv) State the observation when the reaction occurs.

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

    (d) Substance C2H5OH is produced when the compound A reacts with steam through Process

    II.

    (i) Write the equation to show the reaction.

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

    (ii) State the homologous series represented by C2H5OH.

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

    (iii) State one condition to carry out Process II.

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

    Process II

    Process I

    Reagent B

    Steam

    C2H4Br2

    C2H5OH

    Compound A

    Diagram 4

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    [1 mark]

    5. Table 5 below shows four types of industrial products immediately.

    Type of industrial product Example Composition

    Glass SSilica, lead(II) oxide

    Polymer Polyvinyl chloride, PVCVinyl chloride

    Alloy T Copper and tin

    U BricksSilica, aluminium oxide an