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8/8/2019 2007 MRSM P2
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Paper 2 MRSM 2007
1 aDaZ Jan09
Section A
1. Diagram 1 shows the electronic arrangement of atoms of six elements.
P, Q, R, S, T and U do not represent the actual symbol of the elements. Use the
letters to answer the following questions.
Diagram 1
(a). Determine and fill the position of P and T in the Periodic Table of
Elements given below.[2M]
Q R
S U
(b) State one element which:
(i) is a metal : ............................................................................................. [1M]
(ii) forms an ion with +2 charge : ................................................................ [1M]
(iii) is used in advertising light: ................................................................... [1M]
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(c) Name the products formed when S reacts with water.[2M]
……………………………………………………………………………………………………….
(d) State one usage of U in water treatment plant. [1M]
……………………………………………………………………………………………………….
(e) The atomic radius of T is smaller than S. Explain why.[1M]
……………………………………………………………………………………………………….
2. Diagram 2 shows the electrolysis of 1.0 mol dm-3 sodium chloride solution
which is still in progress.
Diagram 2
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Paper 2 MRSM 2007
3 aDaZ Jan09
(a) Write the formulae of all ions present in the electrolyte. [1M]
……………………………………………………………………………………………………….
(b) Name the gas produced at:[2M]
(i) burette X : ......................................................................................................
(ii) burette Y : .....................................................................................................
(c)State how you would verify the gas named at b(i).[3M]
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
(d) (i) Write the half-equation for the process that occurs in burette X. [1M]
……………………………………………………………………………………………………….
(ii) At the end of the experiment, 30.00 cm-3 of gas was collected at room
temperature in burette X.
Calculate the number of moles of gas collected in burette X. [1 mol of gas occupies a volume of 24.0 dm3 at room temperature]
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(e) Name a substance that can be used to replace carbon electrodes for the
experiment to get the same result? [1M]
……………………………………………………………………………………………………….
(f) State one usage of the electrolysis of sodium chloride solution in industry.
[1M]
……………………………………………………………………………………………………….
3. (a) Diagram 3 shows a series of tests performed on a colourless solution
which contains one cation and two anions.
Diagram 3
(i) Based on the observations in Diagram 3, complete the table below with
appropriate inferences.[3M]
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Paper 2 MRSM 2007
5 aDaZ Jan09
Test Inference
1
2
3
(ii) Write an ionic equation for the reaction in Test 3.[1M]
……………………………………………………………………………………………………….
(b) A student wants to prepare a pure sample of crystalline zinc sulphate by
reacting dilute sulphuric acid with substance X.
(i) Name the substance X.[1M]
……………………………………………………………………………………………………….
(ii) Write an equation for the above reaction.[1M]
……………………………………………………………………………………………………….
(iii) Calculate the maximum mass of zinc sulphate that can be prepared if
50.0 cm3 of 0.2 mol dm-3 sulphuric acid is reacted with excess X. [3M]
[The relative formula mass of zinc sulphate = 161]
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4. An experiment is carried out to study the effect of concentration on rate of
reaction.
50.0 cm3 of 0.5 mol dm-3 hydrochloric acid and excess granulated calcium
carbonate is put into a conical flask and is placed on an electronic balance
as shown in Diagram 4. The mass of the conical flask and its contents is recorded at 60 seconds
intervals.
Diagram 4
Table 4 shows the results.
Time/s. 0 60 120 180 240 300 360 420 480
Balance readings/g 140.64 140.48 140.37 140.31 140.26 140.22 140.20 140.20 140.20
Table 4
(a) Give the definition of rate of reaction. [1M[
……………………………………………………………………………………………………….
(b) Explain why the mass of the conical flask and its content decreases with
time. [1M]
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
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Paper 2 MRSM 2007
7 aDaZ Jan09
(c) Based on Table 4, plot a graph of the mass of the conical flask and its
content versus time on the graph paper below. [3M]
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(e) (i) Calculate the mass of carbon dioxide gas produced. [1M]
(ii) Calculate the expected volume of gas produced at room condition.
[1 mol of gas occupies 24 dm3
at room condition; relative molecular mass of CO2 is 44]
5. Diagram 5 shows a series of chemical reactions starting from compound Y.
Diagram 5
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Paper 2 MRSM 2007
9 aDaZ Jan09
(a) Name compound Y. [1M]
……………………………………………………………………………………………………….
(b) Draw a diagram to show the set-up of apparatus if Process I is to be carried
out in a laboratory. [2M]
Name of compound P : .........................................................
(d) Describe how Process III could be done in a laboratory. [3M]
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
(e) (i) Name the process that occurred. [1M]
……………………………………………………………………………………………………….
(ii) Write a chemical equation for the above reaction. [2M]
……………………………………………………………………………………………………….
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6. In an experiment to study the heat of neutralization, 25.0 cm3 of a 1.0
mol dm-3 sodium hydroxide solution was added to 25.0 cm-3 of a 1.0 mol dm-3
aqueous hydrochloric acid. The mixture was then stirred and the maximum
temperature was recorded.
Diagram 6 shows the set up of the apparatus used in the experiment.
Diagram 6
The following data was obtained.
Initial temperature of sodium hydroxide solution = 28.5C
Initial temperature of hydrochloric acid solution = 28.5C
Maximum temperature of the mixture = 34.5C
(a) What is meant by heat of neutralization? [1M]
……………………………………………………………………………………………………….
(b) Write an ionic equation for the reaction between hydrochloric acid and
sodium hydroxide. [1M]
……………………………………………………………………………………………………….
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Paper 2 MRSM 2007
11 aDaZ Jan09
(c) Based on the data obtained from the experiment, calculate
(i) the number of moles of hydrochloric acid used. [1M]
(ii) the amount of heat released [1M]
(iii) the heat of neutralization [1M]
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(d) Draw the energy level diagram for the reaction.[2M]
(e) (i) The heat of neutralization obtained from the experiment is less than the
theoretical value. Give a reason. [1M]
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
(ii) Suggest one step that should be taken to modify the apparatus in order to
get a more accurate result. [1M]
……………………………………………………………………………………………………….
……………………………………………………………………………………………………….
(f) The experiment is repeated by doubling the volume of both hydrochloric
acid and sodium hydroxide. Assuming the initial temperature is maintained,
what would be the maximum temperature of the mixture?
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Paper 2 MRSM 2007
13 aDaZ Jan09
Section B
7. (a) Table 7.1 shows information on the atomic structure and the relative
atomic mass of three elements: aluminium, carbon and oxygen.
Element Number of proton Number of neutron Relative atomic mass
Carbon 6 6 12
Oxygen 8 8 16
Aluminium 13 14 27
Table 7.1
(i) Based on Table 7.1, state the relationship between the relative atomic
mass of an element with the number of proton and neutron of its atom. [1M]
(ii) Draw the electronic arrangement diagram for an ion of oxygen. [2M]
(iii) Aluminium and carbon react with oxygen to form aluminium oxide and
carbon dioxide respectively. The reactions are represented by the following
equations.
I. 4 Al + 3O2 → 2 Al2O3
II. C + O2 → CO2
Describe how chemical bonds in aluminium oxide and carbon dioxide are
formed. [8M]
(b) Naphthalene and sodium chloride are white crystals at room temperature.
Table 7.2 shows two physical properties of the compounds.
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Compound Melting point /C Electrical conductivity
Naphthalene 80 Non electrolyte
Sodium chloride 801 Electrolyte
Table 7.2
Explain the differences in the melting points and the electrical conductivity of
naphthalene and sodium chloride.
Your answer should be based on the [5M]
o types of particles present in both compounds
o types of bonds and
o forces of attraction
(c) Diagram 7 shows the symbol of two atoms of oxygen.
Diagram 7
Compare and contrast the two atoms of oxygen.[4M]
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Paper 2 MRSM 2007
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8. (a) Table 8 shows the pH of two solutions.
Solution pH
0.1 mol dm-3 of potassium hydroxide solution 13
0.1 mol dm-3 of aqueous ammonia 11
Table 8
Explain why the two solutions have different pH. [4M]
(b) An unlabeled reagent bottle is said to contain sulphuric acid solution.
Describe how you would confirm the solution. [4M]
(c) The structural formula of ethanoic acid is shown in Diagram 8.
Diagram 8
(i) Explain why ethanoic acid is a monoprotic acid. [2M]
(ii) Glacial ethanoic acid does not conduct electricity but the aqueous solution
of ethanoic acid does. Explain why.[3M]
(iii) When zinc powder is added into an aqueous ethanoic acid, bubbles of
colourless gas are evolved.
Write a chemical equation for the reaction.[2M]
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Paper 2 MRSM 2007
17 aDaZ Jan09
Explain how zinc and tin layers in P and Q protect the iron bars from corrosion.
Determine which iron bar is more protected from corrosion.[6M]
(c) Fe2+ ion can be oxidized to Fe3+ ion while Fe3+ ion can be reduced to Fe2+ ion
as shown in the following half-equations.
Fe2+ Fe3+ + e
Fe3+ + e Fe2+
Design an experiment to show how these two changes can be carried out. Your
answer should consist of the following: [10M]
Chemicals required
Procedure of the experiment
Observation
Overall chemical equation involved in the reaction
10. Sodium stearate and sodium dodecylsulphate are cleaning agents. Their
molecular formulae are shown in Diagram 10.1.
Sodium stearate : CH3(CH2)16COONa
Sodium dodecyl sulphate : CH3(CH2)11OSO3Na
Diagram 10.1
(a) (i) Sodium stearate dissolves in water to form ions. Write an equation to
show the ionization of sodium stearate. [1M]
(ii) Determine which of the two cleaning agents is more effective in their
cleansing action in hard water. Give reasons.[4M]
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(iii) Fat reacts with an alkali to form soap.
Describe an experiment to prepare a sample of soap. Your answer should
include: [8M]
Chemicals used
Procedure
A test to verify the soap sample that you have prepared has a
cleansing effect.
(b) Diagram 10.2 shows the arrangement of atoms of two substances, X and Y
in solid state.
Diagram 10.2
Based on Diagram 10.2, differentiate the arrangement of atoms and the
properties of substance X and Y.[7M]
End Of Question Paper