stpm trials 2009 chemistry paper 2 terengganu

CONFIDENTIAL*

STPM 962/2 [Turn over *This question paper is CONFIDENTIAL until the examination is over. CONFIDENTIAL*

Name : ………………………………………………… NRIC : ………………………… JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PELAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJAR JABATAN PENLAJARAN ERENGGANUJABATANPELAJARAN TERENGGANU JABATANPELAJA Instructions to candidates :

This question paper consists of 11 printed pages

Answer all the questions in Section A in the spaces provided. Answer any four questions from section B. For this section, write your answers on the answer sheets provided. Begin each answer on a fresh sheet of paper. Answers should be illustrated by large, clearly labeled diagrams wherever suitable. Answers may be written in either Malay or English. Arrange your answer in numerical order and tie the answer sheets to this booklet.

For examiner’s use Section Marks Marks

Obtained

A

1 10 2 10 3 10 4 10

40

B

5 15 6 15 7 15 8 15 9 15

10 15 60

TOTAL 100

Two and a half hours

OTI 2 STPM 2009

JABATAN PELAJARAN NEGERI TERENGGANU

962 / 2

CHEMISTRY PAPER 2

STRUCTURE AND ESSAY

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2

Section A (40 Marks)

Answer all questions in this section. 1 (a) The relative atomic mass of X is 79.99. (i) Why is the relative atomic mass of X not a whole number? ……………………………………………………………………………………..

[1 mark]

(ii) In nature, X contains two isotopes with mass numbers 79 and 81. Calculate the percentage abundance of the isotopes 79X and 81X.

[2 marks] (iii) If X exist as a monoatomic element,sketch the mass spectrum of X. [2 marks]

(b) Graph against p for 1.0 mol H2 and CO2 at 273K is shown below:

(i) Explain why carbon dioxide behaves like an ideal gas at low pressure.

…………………………………………………………………………………

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

Ideal gas

CO2 H2

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(ii) What type of deviation from ideal gas behaviour for hydrogen.

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

(iii) Why hydrogen shows only deviation in (ii).

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

2 (a) The following diagram shows an arrangement of an electrochemical cell created from

two half- cells, A and B.

(i) Write the overall equation for the above cell

[1 mark]

(ii) With reference to the Data Booklet, calculate the electromotive force(e.m.f) of the under standard condition.

[3 marks]

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(iii) Using the result obtained in(ii),write the Nernst equation of the above cell reaction.

[1 mark]

(b) (i) On the incomplete outline below sketch the Born-Haber cycle which includes the standard enthalpy change of formation, /\H, and the lattice energy of calcium sulphide. Label all the enthalpy changes involved and the chemical species at each stage. [Abbreviations can be used, as in part (b).]

[5 marks]

Energy

Ca2+(g) + S2-(g)

Ca(s) + S(s)

CaS(s)

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(ii) The standard enthalpy changes of atomisation,

∆H0a of calcium = 178 kJ mol-1

∆H0a of sulphur = 279 kJ mol-1

The sum of the first two electron affinities of sulphur = 337 kJ mol-1 The standard enthalpy change of formation,

∆H0a of calcium sulphide = - 487 kJ mol-1.

First ionisation of Calcium = +590 kJmol-1

Second ionisation of Calcium = +1150 kJmol-1

Calculate the lattice energy of calcium sulphide.

[2 marks] 3 (a) Write the equations for the reaction of ethanoyl chloride, CH3COCl, with 1-propanol,

CH3CH2CH2OH, and aniline, C6H5NH2. Name the organic products formed. (i) 1-propanol

(ii) Aniline

[4 marks]

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(b) Write an equation to show how aniline can be obtained from the product formed in

(a)(ii) above.

[1 mark] (c) Give the formulae of the products obtained when the following ester

is heated with aqueous sodium hydroxide.

[2 marks]

(d) (i) Give the structural formulae of the reagents that are required to produce Compound X, , by a one step reaction.

(ii) State a use for compound X.

[3 marks] 4 (a) When ammonium nitrate is heated,it liberates a colourless gas. The gas can be used as

an anaesthetic. (i) Give the name of the gas

………………………………………………………………….……………

[1 mark] (ii) Write the equation for the above reaction.

…………………………………………………………………………….…

[1 mark]

│ CH2

O ║

O ║

OCH2CHOCCH2CH2C

O-C-CH3

COOH

║ O

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7

On the axes below,sketch the general trend for each property of the elements or their compound the third period of the Periodic Table. No scale is given for the vertical axis.Your sketch is expected to be clear but only qualitative.

Expalain the changes shown.

[1 mark] Explanation

……………………………………………………………………………………….

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

………………………………………………………………………………………..

[3 marks]

(b) Chromium (proton number = 24) is a d-block element. A lot of chromium compound are used in the laboratory.

(i) Write the electronic configuration for the Cr3+ ion.

………………………………………………………………………..………..

[1 mark]

(ii) Briefly explain why the Cr3+ (aq) ion is coloured.

……………………………………………………………………………….

……………………………………………………………………………….

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

.

S Mg

Melting point of oxides (oC)

P Si Al Na

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5 (a) State the difference between the hydrogen emission spectrum and a spectrum produced by a tungsten filament bulb.

[2 marks]

(b) States all the orbitals for the carbon atom and state the differences between them. [2 marks]

(c) Hund`s rule, Pauli exclusion principle and Aufbau principle are used to determine the ground states electronic configuration of an atom.

(i) State the rule and principles. [3 marks]

(ii) Describe how the two principles are applied to oxide ion O2-, as an example.

[3 marks]

(d) (i) What is meant by the atomic radius of an element? [ 1 mark]

(ii) State and explain the changes in the radius of the atom of elements in Period 2, that is, from lithium to neon.

[4 marks]

6 (a) Predict the shape of the NH3 molecules and NH4

+ ions , explain the differences in their bond angel.

[4 marks] (b) Draw a labeled diagram showing the overlapping of orbitals in (i) H2O

[2 marks] (ii) C2H4

[2 marks] (c) The boiling point of H2O is higher than HF.Explain.

[2 marks]

(d) The rate of decomposition of acidic hydrogen peroxide can be analysed through titration. Hydrogen peroxide samples with a fixed volume are taken at specific times and were titrated with potassium manganate(IV) solution. The titration results are as follows:

Time/min

0 10 20 30

Volume of KMnO4(aq)/cm3

45.5 27.4 16.4 9.9

(i) Determine the half-life of this reaction by plotting the graph, using the data

from the table above. [4 marks]

(ii) What is the order of this reaction? [1 mark]

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7 (a) State Le Chatelier’s principle. [2 marks]

Referring to the equilibrium

(b) Explain

(i) the effect on the yield of NO when pressure on equilibrium mixture is increased

(ii) the effect on equilibrium constant, Kc when temperature on the equilibrium mixture is decreased.

[4 marks]

(c) If 0.40 mol of NH3 and 0.50 mol of O2 in a 1 dm3 container is allowed to react in the presence of catalyst Platinum/Rhodium until an equilibrium is established, the yield of NO is 30% by mole. Calculate the number of mol of NO produced.

[2 marks] Given that the reaction is second order.

(d) Sketch the graphs of (i) concentration of A versus time and (ii) rate versus

concentration of A. [2 marks]

(e) If the graph of ]A[

1 versus time is as given below.

Calculate (i) the rate constant (ii) the initial concentration of

A

[3 marks]

(f) Suggest the mechanism for the reaction [2 marks]

A B

A B

4NH3(g) + 5O2(g) 4NO(g) + 6H2O(g) ∆H = –908 kJ mol–1

t / min

]A[1

/ mol–1 dm–3

20 0

2.0

12.

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8 (a) Describe and explain the variation in boiling point of the tetrachlorides of Group 14 from Carbon to lead [4 marks]

(b) How and why do CCl4 and SiCl4 differ in their reaction with water? Include,in your answer any reaction that occurs. [4 marks]

(c) Suggest a use of each element or compound below, and explain how each of the uses is related to physical or chemical properties and structure.

(i) Silicon (ii) Silicon (IV) oxide (iii) Carbon dioxide

[3 marks]

(d) Aluminium is extracted from a mixture of molten aluminium oxide and cryolite, Na3AlF6 by electrolysis. Suggest factors that have to be taken into consideration when choosing a site for an aluminium factory.

State one adverse effect on the environment as a result of the extraction process of aluminium.

[4 marks]

9 (a) An alkene, C4H8 reacts with hydrogen chloride to produce a compound, C4H9Cl, draw the structure of the alkene and the chloro-compound.

[2 marks]

(b) With reference to the reaction scheme below.:

(i) Identify compounds A to E.

(ii) Name the reagent used in step I.

(iii) Give an important use for compound E. [7 marks]

NaOH reflux

A C2H6

B

180oC Conc. H2SO4

C D Br2/CCl4 NaOH

E

Cl2/ light

Reflux

Step 1

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(c) Suggest how you would differentiate the following pairs of compounds by chemical means.

(i) 1-iodohexane and 1-chlorohexane

(ii) chlorocyclohexane and chlorohexane

(iii) 1-chloro-1- butane and 1- chlorobutane [6 marks]

10 (a) The structural formulae of two amines are shown below.

Which is the stronger base? Explain

[2 marks] (b) Suggest ,with reasons.how the basicity of 3,4-difluorophenylamine might campare

with that of phenylamine.

[2 marks] (c) Ziegler-Natta catalyst is a mixture of titanium(IV) chloride, TiCl4 and

triethylaluminium, Al(CH3CH2)3, Explain the addition polymerisation mechanism with the ziegler-Natta catalyst to produce poly(ethene).

[6 marks]

(d) Give two advantages of addition polymerisation with the Ziegler-Natta catalyst campared to addition with free radical polymerisation in the production of poly(ethene)

[3 marks] (e) Nylon has similar characteristics with a few natural compounds.What are these

compound? Explain. [2 marks]

END OF QUESTION PAPER

Tetrahyroquinoline

Tetrahydroisoquinoline

3,4-Difluorophenylamine

stpm trials 2009 chemistry paper 2 terengganu

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