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Microsoft Word - 2CA_S6_Mock_exam_paper_1_2019_engCHEMISTRY Mock
Exam Paper
HKDSE CHEMISTRY — A Modern View (Second Edition) Mock Exam Paper 1
© Aristo Educational Press Ltd 2019 1
HONG KONG DIPLOMA OF SECONDARY EDUCATION EXAMINATION
CHEMISTRY Paper 1
This paper must be answered in English.
GENERAL INSTRUCTIONS 1. There are TWO sections, A and B, in this
Paper. You are advised to finish Section A in about 45
minutes. 2. Section A consists of multiple-choice questions in this
question paper, while Section B contains
conventional questions printed separately in Question-Answer Book
B. 3. Answers to Section A should be marked on the Multiple-choice
Answer Sheet while answers to Section
B should be written in the spaces provided in Question-Answer Book
B. The Answer Sheet for Section A and the Question-Answer Book for
Section B will be collected separately at the end of the
examination.
4. A Periodic Table is printed on the back of Question-Answer Book
B. Atomic numbers and relative
atomic masses of elements can be obtained from the Periodic
Table.
INSTRUCTIONS FOR SECTION A (MULTIPLE-CHOICE QUESTIONS)
1. Read carefully the instructions on the Answer Sheet. Write your
name, class and class number in the space provided.
2. When told to open this book, you should check that all the
questions are there. Look for the words
‘END OF SECTION A’ after the last question. 3. All questions carry
equal marks. 4. ANSWER ALL QUESTIONS. You are advised to use an HB
pencil to mark all the answers on the
Answer Sheet, so that wrong marks can be completely erased with a
clean rubber. You must mark the answers clearly; otherwise you will
lose marks if the answers cannot be captured.
5. You should mark only ONE answer for each question. If you mark
more than one answer, you will
receive NO MARKS for that question. 6. No marks will be deducted
for wrong answers.
CHEMISTRY Mock Exam Paper
HKDSE CHEMISTRY — A Modern View (Second Edition) Mock Exam Paper 1
© Aristo Educational Press Ltd 2019 2
This section consists of two parts. There are 24 questions in PART
I and 12 questions in PART II. Choose the best answer for each
question. Candidates may refer to the Periodic Table printed on the
back of Question-Answer Book B. Part I
1. Which of the following statements is correct?
A. All aqueous solutions contain OH(aq) ions.
B. Under room conditions, the pH of an alkaline solution may be a
negative value.
C. All alkaline substances contain hydroxide ion as their
constituent ions.
D. A ‘corrosive’ hazard warning label must be displayed on a bottle
of alkaline solution.
2. Which of the following processes will NOT produce carbon
dioxide?
A. Adding dilute ethanoic acid to marble
B. Adding water to quicklime
C. Burning butane in air
D. Heating limestone strongly in air
3. A student was asked to identify an element, which has the
following properties:
(1) It is a solid stored in an air-tight reagent bottle at room
temperature.
(2) It is insoluble in water but soluble in non-polar
solvents.
(3) It can oxidize sulphite ions to sulphate ions.
To which group of the Periodic Table does this element
belong?
A. Group I
B. Group III
C. Group V
D. Group VII
4. Which of the following hydroxides CANNOT be prepared by the
given reaction?
A. Fe(OH)2 from the reaction between FeCl2(aq) and excess
NH3(aq)
B. Cu(OH)2 from the reaction between CuSO4(aq) and excess
NaOH(aq)
C. Fe(OH)3 from the reaction between FeCl3(aq) and excess
NH3(aq)
D. Pb(OH)2 from the reaction between Pb(NO3)2(aq) and excess
NaOH(aq)
CHEMISTRY Mock Exam Paper
HKDSE CHEMISTRY — A Modern View (Second Edition) Mock Exam Paper 1
© Aristo Educational Press Ltd 2019 3
5. Which of the following solutions turns blue immediately upon the
addition of 1 M FeSO4(aq)?
A. KI(aq)
B. KOH(aq)
C. K3Fe(CN)6(aq)
D. KSCN(aq)
6. Which of the following statements about covalent bonds is
correct?
A. All atoms in covalent compounds do not carry net charges.
B. The bonding electrons must be evenly distributed between the two
atoms.
C. Atoms of non-metals can form covalent bonds only.
D. In a single covalent bond, the bonding electrons must be
contributed by each bonding atom.
7. Potassium peroxodisulphate (K2S2O8) decomposes to potassium
sulphate, sulphur trioxide and oxygen upon heating. What is the
mole ratio of sulphur trioxide and oxygen produced?
A. 1 : 2
B. 2 : 1
C. 3 : 2
D. 2 : 3
8. The following three set-ups are used to investigate rusting. The
three test tubes are allowed to stand for one week.
(1)
(2)
(3)
Which of the following combinations about the three set-ups is
correct?
Rusting observed No rusting observed
A. Amount of rust: (3) > (2) (1)
B. Amount of rust: (2) > (3) (1)
C. Amount of rust: (1) > (3) (2)
D. Amount of rust: (3) > (1) (2)
cotton wool
anhydrous CaCl2
CHEMISTRY Mock Exam Paper
HKDSE CHEMISTRY — A Modern View (Second Edition) Mock Exam Paper 1
© Aristo Educational Press Ltd 2019 4
9. Which of the following reactions has a negative enthalpy
change?
A. Zn(s) + H2SO4(aq) ZnSO4(aq) + H2(g)
B. 2NH3(g) N2(g) + 3H2(g)
C. CuCO3(s) CuO(s) + CO2(g)
D. 2NaCl(aq) + 2H2O(l) 2NaOH(aq) + Cl2(g) + H2(g)
10. 20.0 cm3 of 0.10 mol dm3 NaOH(aq) is required for the complete
neutralization of 0.568 g of an organic acid, which has a formula
of CnH2n+1COOH. What is the value of n?
(Relative atomic masses: H = 1.0, C = 12.0, O = 16.0)
A. 15
B. 16
C. 17
D. 18
11. Which of the following combinations about the uses of polymers
is correct?
Polymer Use
B. Low-density polyethene Lunch box for fast food
C. Polystyrene Food wrapper
12. Consider the following conversion:
In which step the change in oxidation number of nitrogen is the
greatest?
A. Step 1
B. Step 2
C. Step 3
D. Step 4
Step 2 Step 3 HNO3
Step 4
CHEMISTRY Mock Exam Paper
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© Aristo Educational Press Ltd 2019 5
13. A solution contains Na+, Mg2+, Cl and SO4 2. It is found that
the mole ratio of Na+, Mg2+ and
Cl in the solution is 4 : 5 : 12. If there is 0.100 mol of Na+, how
many moles of SO4 2 are
there in the solution?
A. 0.0125 mol
B. 0.025 mol
C. 0.050 mol
D. 0.100 mol
14. Consider the following set-ups, in which metal X is connected
to the positive terminal of the voltmeter.
Voltmeter reading 1.26 V 0.76 V 1.62 V
Which of the following is the correct ascending order of the
reactivity of W, X, Y and Z?
A. Z < Y < X < W
B. W < X < Y < Z
C. Z < X < Y < W
D. Y < W < X < Z
15. Nitrogen forms nitrogen oxides in thunderstorms:
In which of the above nitrogen-containing species does the nitrogen
atom NOT have an octet electronic arrangement?
A. N2 and NO only
B. NO and NO2 only
C. NO2 only
N2 + O2 2NO 2NO2
CHEMISTRY Mock Exam Paper
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© Aristo Educational Press Ltd 2019 6
16. The pH of 500 cm3 of 0.10 M HCl is found to be 1. Which of the
following actions will NOT change the pH of the hydrochloric
acid?
A. Adding 250 cm3 of distilled water to the acid
B. Adding 5 g of calcium carbonate powder to the acid
C. Adding 5 g of copper powder to the acid
D. Adding 5 g of sodium hydroxide granules to the acid
17. Which of the following observable changes can be made when
adding a very small piece of sodium to 50 cm3 of copper(II)
sulphate solution?
(1) Sodium dissolves in the solution.
(2) A pale blue precipitate forms.
(3) Colourless gas bubbles evolve.
A. (1) and (2) only
B. (1) and (3) only
C. (2) and (3) only
D. (1), (2) and (3)
18. The temperature change of the reaction between 2 M KOH and 2 M
HCl in an insulated container is recorded as follows:
Which of the following statements about the above experiment are
correct?
(1) The reaction is exothermic.
(2) ΔT will be smaller if 2 M HCl is replaced by an equal volume of
2 M CH3COOH.
(3) ΔT will be smaller if 2 M HCl is replaced by 1 M HCl.
A. (1) and (2) only
B. (1) and (3) only
C. (2) and (3) only
D. (1), (2) and (3)
Volume of 2 M HCl(aq) (cm3)
Te m
pe ra
tu re
CHEMISTRY Mock Exam Paper
HKDSE CHEMISTRY — A Modern View (Second Edition) Mock Exam Paper 1
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19. The following set-up is used to determine the empirical formula
of hydrocarbon H:
Which of the following statements about the experiment are
correct?
(1) The experiment should be carried out in the fume cupboard as
there is a risk of explosion of unburnt H.
(2) The number of moles of hydrogen in H can be found from the
increase of mass in tube A.
(3) The number of moles of carbon in H can be found from the
increase of mass in tube B.
A. (1) and (2) only
B. (1) and (3) only
C. (2) and (3) only
D. (1), (2) and (3)
20. Which of the following methods can be used to distinguish
between Na2CO3(s) and NaHCO3(s)?
(1) Heating the two solids separately
(2) Adding hydrochloric acid to the two solids separately
(3) Adding saturated calcium chloride solution to the two solids
separately
A. (1) only
B. (2) only
C. (1) and (3) only
D. (2) and (3) only
21. Aluminium is the most abundant metal in the Earth’s crust.
However, it is still important to recycle aluminium. Which of the
following are the reasons to recycle aluminium?
(1) The extraction of aluminium consumes much electrical
energy.
(2) Aluminium ore is non-renewable.
(3) The extraction of aluminium causes serious pollution.
A. (1) and (2) only
B. (1) and (3) only
C. (2) and (3) only
D. (1), (2) and (3)
gaseous hydrocarbon H
CHEMISTRY Mock Exam Paper
HKDSE CHEMISTRY — A Modern View (Second Edition) Mock Exam Paper 1
© Aristo Educational Press Ltd 2019 8
22. Consider the following polymerization:
Which of the following statements is/are correct?
(1) A mixture of products is produced.
(2) The polymerization occurs at room temperature without using
catalyst.
(3) The polymer produced can dissolve in dilute sulphuric
acid.
A. (1) only
B. (2) only
C. (1) and (3) only
D. (2) and (3) only
23. Which of the following statements about ethanedioic acid are
correct?
(1) Its empirical formula is C2H2O4.
(2) All the hydrogen atoms in an ethanedioic acid molecule are
ionizable.
(3) The basicity of ethanedioic acid is 2.
A. (1) and (2) only
B. (1) and (3) only
C. (2) and (3) only
D. (1), (2) and (3)
24. Consider the following statements and choose the best
answer:
1st statement 2nd statement
Both (NH4)2SO4 and (NH4)2HPO4 have the same percentage by mass of
nitrogen.
Both (NH4)2SO4 and (NH4)2HPO4 are effective nitrogenous
fertilizers.
A. Both statements are true and the 2nd statement is a correct
explanation of the 1st statement.
B. Both statements are true but the 2nd statement is NOT a correct
explanation of the 1st statement.
C. The 1st statement is false but the 2nd statement is true.
D. Both statements are false.
CHEMISTRY Mock Exam Paper
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© Aristo Educational Press Ltd 2019 9
Part II
25. Which of the following statements about transition metals is
INCORRECT?
A. The melting points of all transition metals are higher than
25C.
B. Iron and its ions can act as catalysts in some reactions.
C. Most compounds of chromium and manganese are coloured.
D. Nickel and cobalt form compounds with variable oxidation
states.
26. Which of the following compounds is optically active?
A.
B.
C.
D.
27. NO(g) and O2(g) are added to a 2 dm3 sealed container. The
following reaction occurs:
2NO(g) + O2(g) 2NO2(g)
The change in number of moles of NO(g) is shown in the following
table.
Time (s) 0 1 2 3 4 5
Number of moles of NO(g) (mol)
0.020 0.010 0.008 0.007 0.007 0.007
What is the rate of consumption of O2(g) in the first two
seconds?
A. 0.0450 mol dm3 s1
B. 0.0060 mol dm3 s1
C. 0.0030 mol dm3 s1
D. 0.0015 mol dm3 s1
CHEMISTRY Mock Exam Paper
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28. When 0.12 g of sodium is added to water, 51.9 cm3 of hydrogen
is produced at room temperature and pressure.
2Na(s) + 2H2O(l) 2NaOH(aq) + H2(g)
What is the percentage yield of hydrogen?
(Relative atomic mass: Na = 23.0; molar volume of gas at room
temperature and pressure = 24.0 dm3 mol1)
A. 41.4%
B. 82.9%
C. 95.6%
D. 100%
What is the major product Y?
A. CH3CH2CH2CH2Br
B. CH3CH2CHBrCH3
C. CH3CHBrCHBrCH3
D. CH2BrCH2CH2CH2Br
30. Paradol is a compound that can be found in ginger. Its
structure is shown below:
Which of the following statements about paradol is correct?
A. It is insoluble in water.
B. The carbonyl group can be oxidized to a hydroxyl group.
C. It can undergo addition polymerization.
D. It exhibits enantiomerism.
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31. Consider the following three equilibrium systems:
(1) PCl5(g) PCl3(g) + Cl2(g)
(2) H2(g) + I2(g) 2HI(g)
(3) 2NO(g) + O2(g) 2NO2(g)
Initially, the underlined species have the same equilibrium
concentration. The volumes of the equilibrium mixtures are then
reduced by half at the same temperature. What is the correct order
of the concentrations of the underlined species when the reactions
restore equilibrium?
A. [PCl3] > [HI] > [NO2]
B. [HI] > [NO2] > [PCl3]
C. [NO2] > [PCl3] > [HI]
D. [NO2] > [HI] > [PCl3]
32. Which of the following compounds can react with NaBH4(aq) to
form an alcohol?
(1)
(2)
(3)
A. (1) and (2) only
B. (1) and (3) only
C. (2) and (3) only
D. (1), (2) and (3)
33. Gases X and Y are mixed in a closed container at 298 K. They
react and finally reach an equilibrium. The following table shows
the changes in concentrations of the gases:
Gas X Y Z
Initial concentration (mol dm3) 0.10 0.20 0
Final concentration (mol dm3) 0.05 0.05 0.10
Which of the following information can be obtained from the given
data?
(1) The reaction involved is X(g) + Y(g) 2Z(g).
(2) The value of Kc for this reaction is 1600 mol2 dm6.
(3) The system is a homogeneous equilibrium.
A. (1) only
B. (2) only
CHEMISTRY Mock Exam Paper
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© Aristo Educational Press Ltd 2019 12
34. Consider the following chemical equilibrium in a sealed
container:
2NO(g) + 2CO(g) N2(g) + 2CO2(g)
Which of the following can indicate that an equilibrium has been
established?
(1) When two moles of nitrogen monoxide is consumed, one mole of
nitrogen forms.
(2) The pressure of the reaction mixture remains unchanged.
(3) The density of the reaction mixture remains unchanged.
A. (1) only
B. (2) only
35. Element P can undergo the following reactions:
Which of the following statements about element P are
correct?
(1) P must be a transition metal which can form compounds of
variable oxidation states.
(2) P may be iron.
(3) Q is an oxidizing agent.
A. (1) and (2) only
B. (1) and (3) only
C. (2) and (3) only
D. (1), (2) and (3)
36. Consider the following statements and choose the best
answer:
1st statement 2nd statement
Aspirin can be regarded as a polyester. Aspirin contains an ester
group.
A. Both statements are true and the 2nd statement is a correct
explanation of the 1st statement.
B. Both statements are true but the 2nd statement is NOT a correct
explanation of the 1st statement.
C. The 1st statement is false but the 2nd statement is true.
D. Both statements are false.
END OF SECTION A
where m > n
CHEMISTRY Mock Exam Paper
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B
CHEMISTRY Paper 1 (MOCK EXAMINATION)
SECTION B : Question-Answer Book B
This paper must be answered in English.
INSTRUCTIONS FOR SECTION B (1) Write your name, class and class
number in the space
provided on this page.
(2) Refer to the general instructions on the cover of the Question
Paper for Section A.
(3) This section consists of TWO parts, Part I and Part II.
(4) Answer ALL questions in both Parts I and II. Write your answers
in the spaces provided in this Question- Answer Book. Do not write
in the margins. Answers written in the margins will not be
marked.
(5) An asterisk (*) has been put next to the questions where one
mark will be awarded for effective communication.
(6) Supplementary answer sheets will be provided on request. Write
your name, class, class number and question number on the answer
sheets and fasten them with a string INSIDE this Question-Answer
Book.
(7) No extra time will be given to you for filling in your name,
class and class number in the Question- Answer Book after the ‘Time
is up’ announcement.
Name
Class
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PART I Answer ALL questions. Write your answers in the spaces
provided.
1. Aluminium and iron are the first two most abundant metals in the
Earth’s crust. They are widely used today.
(a) The electronic arrangement of an iron atom is 2, 8, a, 2.
Deduce the value of a.
(1 mark)
(b) The bonding in aluminium and iron are similar. Describe the
bonding of metals in solid state.
(1 mark)
(c) Complete the following table by stating the natural source and
the method of extraction from the source for each metal.
Metal Natural source Method of extraction
Aluminium
Iron
(d) The uses of metals are related to their properties.
(i) Suggest one property of iron which makes it suitable for making
car bodies.
(ii) Suggest one property of aluminium which makes it suitable for
making kitchen foil.
(2 marks)
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2. For each of the following experiments, state the expected
observable change(s) and write the ionic equation(s) for the
reaction(s) involved.
(a) Bubbling ammonia gas into copper(II) sulphate solution until in
excess
(4 marks)
(2 marks)
(c) Adding chlorine water to potassium iodide solution until in
excess
(2 marks)
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3. Propane can be used as fuel in fuel cells. In the following fuel
cell, concentrated sulphuric acid is the electrolyte.
(a) Write the half equations for the reaction occurring at
(i) the anode, and
(2 marks)
(b) Write the overall equation for the reaction occurred in the
fuel cell.
(1 mark)
(c) The membrane for proton exchange only allows protons to pass
through. Label the direction of the flow of protons () in the fuel
cell.
(1 mark)
(d) The electrolyte used contains 98% of sulphuric acid by mass and
its density is 1.83 g cm3. Calculate the concentration, in mol dm3,
of sulphuric acid in the electrolyte.
(Relative atomic masses: H = 1.0, O = 16.0, S = 32.1)
(2 marks)
C3H8
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4. Methane reacts with chlorine when exposed to sunlight.
Chloroform (CHCl3) is one of the products of the reaction. It is an
oily liquid that floats on sodium chloride solution.
(a) What would be observed when the reaction between methane and
chlorine has started?
(1 mark)
(b) Name the type of reaction between methane and chlorine.
(1 mark)
(c) Besides chloroform and hydrogen chloride, write the chemical
formula of another chlorine-containing product of this
reaction.
(1 mark)
(d) Chloroform vapour undergoes oxidation on standing in air in the
presence of light to form phosgene (COCl2) and hydrogen
chloride.
(i) Write the chemical equation for the reaction involved.
(ii) Phosgene is a highly toxic gas. Suggest a chemical test to
show whether the oxidation of chloroform has occurred.
(3 marks)
saturated NaCl(aq)
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5. An iron oxide is reduced to iron using the following
set-up:
(a) What type of structure does the iron oxide have?
(1 mark)
(b) Draw the electron diagram for a carbon monoxide molecule,
showing electrons in the outermost shells only.
(1 mark)
(c) With the aid of a chemical equation, state the function of
limewater in the set-up.
(2 marks)
(d) Carbon monoxide is highly toxic. Suggest one safety precaution
in carrying out this experiment.
(1 mark)
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5. (e) Let the chemical formula of the oxide be FexOy. Write a
chemical equation for the reaction between the oxide and carbon
monoxide in terms of x and y.
(1 mark)
(f) 1.60 g of the oxide is heated until red hot. Then carbon
monoxide is passed over the heated oxide and 1.12 g of iron is
obtained. Calculate the empirical formula of this oxide.
(Relative atomic masses: O = 16.0, Fe = 55.8)
(2 marks)
*6. With the aid of chemical equations, outline how you would carry
out tests to distinguish three gases: carbon dioxide, sulphur
dioxide and nitrogen monoxide.
(5 marks)
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7. A student carried out the electrolysis of acidified potassium
dichromate solution.
(a) State what would be observed at the iron electrode.
(1 mark)
(b) During the electrolysis, the electrolyte turns from orange to
green.
(i) Write the half equation for the reaction involved.
(ii) Is this reaction an oxidation or a reduction?
(2 marks)
(c) When the electrolysis has been run for some time, colourless
gas bubbles are seen on the graphite electrode. Suggest what the
gas bubbles are and explain the formation of the gas with the aid
of a half equation.
(3 marks)
(d) In electroplating industry, the effluent containing dichromate
ions is treated by electrolysis as shown above. The solution
obtained after electrolysis contains several metallic ions. How
should the solution be treated so as to minimize the impact on the
environment?
(2 marks)
graphite electrode iron electrode
acidified potassium dichromate solution
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8. Ethene can be prepared from the dehydration of ethanol by
concentrated sulphuric acid at high temperatures. The following
equation shows the reaction involved:
CH3CH2OH(g) CH2=CH2(g) + H2O(g)
(1 mark)
(b) State one safety precaution when heating the mixture of ethanol
and concentrated sulphuric acid.
(1 mark)
(c) Suggest a test to show that the product mixture contains an
unsaturated compound.
(2 marks)
(d) Calculate the enthalpy change of the above reaction by using
the data in the table below:
Reaction Enthalpy change
2CH3OH(g) CH2=CH2(g) + 2H2O(g) ΔH2 = 29.2 kJ mol1
CH3CH2OH(g) CH3OCH3(g) ΔH3 = +50.7 kJ mol1
(3 marks)
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PART II
9. The following equation shows the reaction between propanone and
iodine in the presence of dilute sulphuric acid:
The diagram below shows an instrument used to follow the progress
of the reaction.
(a) Name the above instrument.
(1 mark)
(b) What is the physical parameter of the reaction mixture measured
by the instrument?
(1 mark)
(c) Sketch a graph of the physical parameter against time.
(1 mark)
colour filter
light source
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9. (d) Describe briefly how to show that dilute sulphuric acid is
the catalyst for the reaction. State the expected result.
(2 marks)
(e) Suggest another reaction for which the progress of the reaction
can also be followed by the above instrument.
(1 mark)
*10. Arrange magnesium, aluminium, silicon and phosphorus in
increasing order of melting points. Explain your answer in terms of
bonding and structure.
(5 marks)
CHEMISTRY Mock Exam Paper
HKDSE CHEMISTRY — A Modern View (Second Edition) Mock Exam Paper 1
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11. Ethanol can be prepared from the reaction between carbon
dioxide and hydrogen. The equilibrium constant of the reaction at
298 K is 2.95 × 1011 mol4 dm12.
2CO2(g) + 6H2(g) CH3CH2OH(g) + 3H2O(g)
(a) A student thinks that the reaction at 298 K should be very fast
as the value of Kc is very large. Do you agree? Explain
briefly.
(1 mark)
(b) At different temperatures and constant pressure, the percentage
of carbon dioxide reacted is shown below.
Volume ratio of
1.5 45 20
2.0 60 28
3.0 83 37
(i) Deduce whether the forward reaction is exothermic or
endothermic.
(ii) What are the theoretical conditions for a high yield of
ethanol? Explain briefly.
(iii) Comment on whether it is possible to employ these theoretical
conditions in industry.
(5 marks)
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(2 marks)
(b) Name the type of reaction involved between wintergreen oil and
sodium hydroxide solution.
(1 mark)
(c) Suggest a chemical test to distinguish between wintergreen oil
and Y.
(2 marks)
NaOH(aq) X
heat Y
CHEMISTRY Mock Exam Paper
HKDSE CHEMISTRY — A Modern View (Second Edition) Mock Exam Paper 1
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13. When heating calcium ethanoate strongly, acetone is produced.
Acetone is a common solvent used in the school laboratory.
(a) What is the systematic name for acetone?
(1 mark)
(b) Write a chemical equation for the thermal decomposition of
calcium ethanoate.
(1 mark)
(c) Acetone can be converted to isopropyl alcohol.
(i) Draw the structural formula of isopropyl alcohol.
(ii) Suggest the reagents required for the conversion.
(iii) Which compound, acetone or isopropyl alcohol, has a higher
boiling point? Explain your answer.
(4 marks)
CHEMISTRY Mock Exam Paper