CHEMISTRY

Name : ………………………………………………… Class : ………..…….…..

I.C Number : ……………………………........…………

CHEMISTRY 962
PAPER 1
NOVEMBER 2020
1 ½ hours

KOLEJ TINGKATAN ENAM SHAH ALAM
JALAN TIMUN 24/1

SHAH ALAM SELANGOR DARUL EHSAN

PROGRAM PENINGKATAN PRESTASI SEMASA PKPB 2020
(Online)

CHEMISTRY 962/1

PAPER 1

DURATION: 1 HOUR 30 MINUTES

DO NOT OPEN THIS BOOKLET UNTIL YOU ARE For examiner’s use
TOLD TO DO SO Section A

Write your name, I.C number and class in the spaces 1 - 15
provided. Section B

There are fifteen questions in Section A. For each 16
question, four choices of answers are given. Choose 17
one correct answer and indicate it on the Multiple-
choice Answer sheet provided. Answer all questions. Section C

Answer all the questions in Section B. Write your TOTAL
answers in the spaces provided.

Answer two out of the 3 questions in Section C. Write
your answer on your examination test pad. All
working should be shown. Numerical answers should
be given to an appropriate number of significant
figures; units should be quoted wherever appropriate.
Begin each answer on a fresh sheet of paper and
arrange your answers in numerical order.

This question paper consists of 8 printed pages

Prepared by: Checked by: Validated by:
………………………….…….….
………………………………...… …………………………………… Puan Shirin Ahmad Sapiuddin
Pn Marini Binti Abd Ghani Pn Maziah Binti Muhamad Zain Form 6 Senior Assistant
Head of Chemistry Unit Science and Mathematics
Head of Department 1

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SECTION A [15 marks]
Answer all questions in this section. Indicate the correct answer on the objective answer sheet.

1. Iodine -123 is used in brain imaging and iodine-131 is used in detecting the activity of thyroid.

Both isotopes

A are stable B have different crystal structures

C react with aqueous solution of KI D have different number of protons

2. An element X with a relative atomic mass of 28.1 consists of isotopes 28X, 29X and 30X. If the
percentage abundance of 29X and 30X are the same , what is the percentage abundance of 28X?

A 0.32 B 3.33 C 93.3 D 96.7

3. Which orbital diagram shows the filling of electron(s) based on Hund’s rule?
AB

CD

4. A non-ideal gas is
A a gas with negligible intermolecular attractive forces
B a gas with negligible gas particle volume
C a gas whose intermolecular attractive forces are strong.
D a gas that obeys the ideal gas equation.

5 Which statement is not true about s, p and d orbitals?
A Three 2p orbitals have the same shape and energy.
B The size of 1s orbital is smaller than that of 2p orbitals.
C 2s orbital is non-directional whereas 2px orbital is directional.
D Vacant 3d orbitals are at a lower energy level than a vacant 4s orbital.

The diagram below shows the bond angle of water and hydrogen sulphide.
6.

The bond angle of water is greater than hydrogen sulphide because
A Oxygen atom is more electronegative than sulphur.
B Sulphur atom is more electronegative than oxygen.
C The force of repulsion between two S-H bonds is greater compares to the O-H bonds.
D The oxygen atom is larger than the sulphur atom.

7 Which ionic compound has the highest covalent character?

A MgO B Al2O3 C MgF2 D AlF3

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8. Which of the following compounds formed co-ordinate bonds?
I H3O+
II [Fe(CN)6]4-

III N2O4

IV PCl5

A I and II B I,II and III C II and IV D I, III and IV

9. Which of the following statements is true concerning the increase of the rate of reaction when
the pressure increased?

A Changes in pressure only affect gaseous and aqueous phase.
B When the pressure increase, the volume that gaseous occupied will decrease.
C More particles have energy greater than the activation energy.
D The activation energy decrease.

10. The equation for the reaction between P and Q is shown below.

2P (g) + Q(g) → R(g)
The rate of reaction increased eight times when the concentrations of P and Q were doubled. Which
statement is true about the reaction?
A It is a third order reaction.
B The number of collisions increases eight times.
C Average molecular speed of P and Q increases eight times
D It is second order reaction with respect to the concentration of P.

11. The reaction equation between nitrogen monoxide and bromine is shown below.

2NO(g) + Br2(g) → 2NOBr(g) ΔH = -23 kJ
The reaction is second order with respect to nitrogen monoxide and first order with respect to
bromine. Which statement is not true of the reaction?

A The rate equation is rate= k [NO]2[Br2].
B The rate constant increases with temperature.
C The enthalpy change of the reaction is -23 k J
D The rate of reaction increases eight times as the volume of the vessel increases two times.

12. The industrial production of nitric acid by the Ostwald process involves the following reaction:

4NH3(g) + 5O2(g) ⇌ 4NO(g) + 6H2O(g) ΔH= - 907 kJ

Which statement is true about the reaction?

A Pt - Rh will increase the yield of NO.
B An increase in pressure will increase the oxidation of NH3.
C An increase in temperature will reduce the equilibrium constant
D A larger vessel will decrease the amount of NO formed.

13. The reforming of methane is the principal commercial source of hydrogen gas. The equation for the
endothermic reaction involved is as follows:

CH4 (g) + H2O (g) CO (g) + 3 H2 (g)

At equilibrium, the quantity of hydrogen gas formed can be increased by

A adding a suitable catalyst B increasing the temperature
C adding a dehydrating agent D reducing the volume of the vessel

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14. The equation of a Haber Process is shown below. ∆H=- 92kJ
N2(g) + 3H2(g) ⇌ 2NH3(g)

A high yield of NH3 is obtained by

A Increasing the temperature to above 400‫ﹾ‬C.
B Increasing the pressure to above 200 atm
C Adding argon at constant volume.
D Using iron filling.

15. The equilibrium system of the decomposition of carbon dioxide to carbon monoxide and
oxygen is shown in the equation below.
2CO2(g) ⇌ 2CO(g) + O2(g) ∆H=+566kJ
Which of the following increases the value of equilibrium constant,Kp of the system?

A Lowers the pressure
B Increases the temperature
C Increases the volume of CO2
D Addition of catalyst

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NAME:…………………………………………………
I.C NUMBER:…………………………………
INDEX NUMBER:………………………………………. SCORE:

962/1

KOLEJ TINGKATAN ENAM SHAH ALAM

PROGRAM PENINGKATAN PRESTASI SEMASA PKPB 2020
CHEMISTRY
PAPER 1

One hour 30 minutes

SECTION A

1. =A= =B= =C= =D=
2. =A= =B= =C= =D=
3. =A= =B= =C= =D=
4. =A= =B= =C= =D=
5. =A= =B= =C= =D=
6. =A= =B= =C= =D=
7. =A= =B= =C= =D=
8. =A= =B= =C= =D=
9. =A= =B= =C= =D=
10. =A= =B= =C= =D=
11. =A= =B= =C= =D=
12. =A= =B= =C= =D=
13. =A= =B= =C= =D=
14. =A= =B= =C= =D=
15. =A= =B= =C= =D=

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Section B [15 marks]

Answer all questions in this section

16. (a) Element M is a monoatomic gas under room temperature and pressure.
[R=8.31 JK-1mol-1]

(i) Given the density of gas M at room temperature and pressure is 0.163 g dm-3, calculate the

molecular mass of M. [3 marks]

(ii) From the molecular mass calculated in (a)(i), deduce gas M and state the ideal behavior of gas

M under room temperature and pressure. [2 marks]

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

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(iii) In the graph of PV/ RT against P below, sketch and labelled the line for an ideal gas and gas M
[2 marks]

PV/RT

P / atm

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17 Sulphuric acid, H2SO4, is manufactured by the Contact process. One of the important reaction

in this process is as follows:

2 SO2 (g) + O2 (g) 2 SO3 (g); ∆H = – 197 kJ mol-1

At 1000 K, equilibrium was achieved when the partial pressures of SO2, O2 and SO3 gases in

the mixture are 0.456 atm, 0.180 atm and 0.364 atm respectively.

(a) Define the term partial pressure. [1 mark]

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

(b) Write an expression for the equilibrium constant, Kp, for the reaction in terms of [1 mark]
partial pressures

(c) Calculate the value of Kp at 1000 K. [2 marks]

(d) Explain the effect on the position of equilibrium if

i. The total pressure of the system is reduced to 0.850 atm. [2 marks]

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

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

ii. Helium gas is added to the mixture but the total pressure is maintained at its original value.
[2 marks]

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Section C [30 marks]
Answer any two questions in this section.

18. In a study of synthetic fuels, 0.100 mol of CO and 0.100 mol of water vapor are added to a

20.0 dm3 container at 900°C, and they react to form CO2 gas and H2 gas. At equilibrium, [CO]
is 2.24 x 10-3 mol dm-3. [Given the gas constant , R=8.31 J mol-1 K-1]

(a) Calculate Kc at this temperature. [4 marks]

(b) Calculate Ptotal in the flask at equilibrium [3 marks]

(c) Explain the effect of this endothermic reaction with an increase in temperature on

(i) the concentration of each component in the equilibrium, [4 marks]

(ii) the rate of attainment/achievement of the equilibrium [4 marks]

19. [1 mark]
(a) (i) State Dalton’s law for a mixture of gases.

(ii) A 2.50 dm3 closed vessel contains nitrogen and xenon at a pressure of 58.5kPa and

a temperature of 320K. If the partial pressure of xenon is 25.8kPa, what is the

mass of nitrogen in the mixture? [4 marks]
(iii) Calculate the pressure of the gas if the mixture is placed in a 1.50dm3 vessel.

[2 marks]
(b) (i) Helium has a triple point temperature of 1.0K and a critical point temperature of

5.0K. Solid helium has the same density as liquid helium.

i) Draw a labelled phase diagram for helium. [3 marks]

(ii) ii) State and explain the effect on the melting point of helium when the pressure is increased.

[2 marks]

(c) Carbon dioxide gas from a fire extinguisher is often used to put out small fires. A fire extinguisher
cylinder has an internal volume of 2.00 dm3 and contains 1.80 kg of carbon dioxide. Calculate the

pressure of carbon dioxide gas in the cylinder at 25.0°C. [3 marks]

20. (a) Define rate law for a chemical reaction. [2 marks]

(b) The combustion of nitrogen monoxide, NO, produces nitrogen dioxide, NO2. The results of

three experiments carried out at a constant temperature are given below.

Experiment [NO] / mol dm3 [O2] / mol dm3 Initial rate of reaction/
mol dm3 s-1
1 0.800 0.160
2 0.200 0.160 6.62 x 10-4
3 0.800 0.320 4.14 x 10-5
1.33 x 10-3

(i) Write the reaction equation for the combustion of nitrogen monoxide. [1 mark]

(ii) Determine the rate law for the combustion of nitrogen monoxide and calculate the rate

constant. [7 marks]

(iii) Explain the effects on the reaction rate and rate constant when [NO] is tripled and [O2] is

decreased eight times. [5marks]

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