hkdse chem fx mock exam paper 1 2012 set 1 eng

HONG KONG DIPLOMA OF SECONDARY EDUCATION EXAMINATION

CHEMISTRY PAPER 1

(MOCK EXAMINATION)

Time allowed: 2 hours 30 minutes

This paper must be answered in English.

GENERAL INSTRUCTIONS

1. There are TWO sections, A and B, in this Paper. Section A carries 36 marks and Section B carries 84 marks. You are advised to finish Section A in about 45 minutes and Section B in about 105 minutes.

2. Section A consists of multiple-choice questions in this question book, 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 must be handed in separately at the end of the examination.

SECTION A (MULTIPLE-CHOICE QUESTIONS)

INSTRUCTIONS FOR SECTION A

1. Read the instructions on the Answer Sheet carefully. 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 should 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.

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.

HKDSE CHEMISTRY Mock Exam Paper 1 (Set 1) CHEMISTRY© Aristo Educational Press Ltd. 2011 1

Set 1

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 this Question Book.

PART I

1. Which of the following reactions involve oxygen gas?

(1) ‘Pop’ sound test of hydrogen

(2) Burning of petrol in car engine

(3) Corrosion of sodium metal

A. (1) and (2) only

B. (1) and (3) only

C. (2) and (3) only

D. (1), (2) and (3)

2. Non-metal elements X and Y are in the same group of the Periodic Table. Element X has a greater atomic number. Which of the following statements are correct?

(1) Atomic size of X is smaller than that of Y.

(2) X is less reactive than Y.

(3) X and Y have different physical properties.

A. (1) and (2) only

B. (1) and (3) only

C. (2) and (3) only

D. (1), (2) and (3)

3. The table below shows the number of neutrons and the number of electrons in five given atoms/ions:

Atom/ionNumber of

neutrons electrons

X 8 8

Y 8 6

Z2+ 12 10

Q2− 9 10

R+ 12 10


Which of the following atoms is an isotope of X?

A. Y

B. Z

C. Q

D. R

4. X, Y, and Z are three metals. X can be extracted from its oxide by carbon reduction and Y can be extracted by direct heating of its oxide. Z cannot be extracted by such methods. Which of the following statements is correct?

A. Z is the least reactive one.

B. Y is more reactive than X.

C. Y should be discovered before Z.

D. X is probably calcium.

5. Given three metals, X, Y and Z. The table below lists the results of their reactions with different substances.

X Y Z

Reaction with dilute hydrochloric acid

explosive reaction slow reaction steady reaction

Reaction with steam

vigorous reaction ? no reaction

Reaction with cold water

steady reaction no reaction no reaction

Arrange the reactivity of X, Y, and Z in descending order.

A. X, Z, Y

B. Y, Z, X

C. X, Y, Z

D. Z, Y, X

6. Which of the following substances contains the same number of ions as 2.340 g of sodium chloride does?

(Relative atomic masses: Na = 23.0, Cl = 35.5, K = 39.1, Zn = 65.4, Ca = 40.1, S = 32.1, O = 16.0, Mg = 24.3, Br = 79.9)

A. 2.984 g of potassium chloride

B. 3.125 g of zinc chloride

C. 3.598 g of calcium sulphate

D. 5.529 g of magnesium bromide


7. An element forms a compound X2Cl3 which contains 25% by mass of chlorine. What is the relative atomic mass of the element X?

(Relative atomic mass: Cl = 35.5)

A. 39.9

B. 79.9

C. 106.5

D. 159.8

8. Car exhaust pipes made of iron rust rapidly. Which of the following are correct reasons?

(1) The temperature of car exhaust pipes is high.

(2) Car exhaust contains water vapour.

(3) Car exhaust contains acidic gases.

A. (1) and (2) only

B. (1) and (3) only

C. (2) and (3) only

D. (1), (2) and (3)

9. Two solutions were mixed in a beaker. The mass of the beaker and contents was then noted at various times. The mass of the beaker and contents is plotted against time as below.

What could the two solutions be?

A. Sodium chloride solution and iron(II) sulphate solution

B. Potassium hydroxide solution and aluminium nitrate solution

C. Potassium carbonate solution and dilute hydrochloric acid

D. Dilute nitric acid and magnesium sulphate solution


Mass of the beaker and contents

Time

10. Which of the following statements about all alkalis is/ are INCORRECT?

(1) They must contain metal ions.

(2) They produce hydroxide ions when dissolved in water.

(3) Their aqueous solutions turn red litmus blue.

A. (1) only

B. (2) only

C. (1) and (3) only

D. (2) and (3) only

11. The table below shows the observations of the chemical tests of three ionic compounds.

CompoundAdding barium chloride solution acidified by dilute HNO3

Adding dilute hydrochloric acid

Flame test

QT White precipitate No observable change Brick-red

XZ Colourless solutionColourless gas

bubblesGolden yellow

X2T White precipitate No observable change Golden yellow

Which of the following combinations of ions involved is most likely to be correct?

X Q T Z

A. Potassium ion Sodium ion Carbonate ion Sulphate ion

B. Sodium ion Calcium ion Sulphate ion Hydrogencarbonate ion

C. Calcium ion Sodium ion Sulphate ion Hydrogencarbonate ion

D. Sodium ion Calcium ion Sulphate ion Carbonate ion

12. After the addition of marble chips to an excess of dilute hydrochloric acid in a conical flask, each of the following was measured and plotted against time on a graph.


Time(min)

If the reaction was complete in 2.5 minutes, which of the following, when plotted against time, would give a graph like the one shown above?

A. Total mass of the conical flask and its contents

B. Volume of carbon dioxide produced

C. pH of the solution

D. Temperature of the solution

13. Which of the following statements about the reaction of propane with bromine in an organic solvent are correct?

(1) The reaction does not occur in darkness.

(2) The reaction is a substitution reaction.

(3) The colour of the reaction mixture fades.

A. (1) and (2) only

B. (1) and (3) only

C. (2) and (3) only

D. (1), (2) and (3)

14. Which of the following is the correct set of numbers which fits into the equation aC4H8 + bO2 cCO2 + dH2O?

a b c d

A. 2 10 8 8

B. 1 6 4 8

C. 1 6 4 4

D. 2 5 3 4

15. Consider the following compounds:

Compound X Compound Y

Which of the following statements about the above two compounds is correct?

A. Both compounds have the same boiling point.

B. Both compounds can turn pH paper to red.

C. Both compounds have the same molecular formula.

D. Both compounds have the same odour.


16. Consider the simple chemical cell shown below.

Which of the following solutions should be used as an electrolyte in order to produce the largest ammeter reading?

A. 0.3 M sulphuric acid

B. 0.5 M sulphuric acid

C. 0.3 M ethanoic acid

D. 0.5 M ethanoic acid

17. Which of the following statements concerning the reaction between chlorine gas and dilute sodium hydroxide solution is/are correct?

Cl2(g) + 2NaOH(aq) NaCl(aq) + NaOCl(aq) + H2O(l)

(1) NaOH(aq) is an oxidizing agent in the reaction.

(2) Cl2(g) is an oxidizing agent in the reaction.

(3) Cl2(g) is a reducing agent in the reaction.

A. (1) only

B. (2) only

C. (1) and (3) only

D. (2) and (3) only

18. Which of the following statements concerning the hydrogen-oxygen fuel cells is/are correct?

(1) They consist of three compartments separated from one another by two porous nickel electrodes.

(2) The porous nickel electrodes can be replaced by graphite rods.

(3) Hydrogen is fed into the cathode compartment and oxygen is fed into the anode compartment.

A. (1) only

B. (2) only

C. (1) and (3) only

D. (2) and (3) only


iron electrode silver electrode

electrolyte

19. Which of the following statements concerning the electrolysis of concentrated sodium bromide solution using graphite electrodes are correct?

(1) The main product at the anode is O2(g).

(2) H+(aq) ions are preferentially discharged at the cathode to form H2(g).

(3) The solution becomes sodium hydroxide solution after electrolysis.

A. (1) and (2) only

B. (1) and (3) only

C. (2) and (3) only

D. (1), (2) and (3)

20. The reaction between zinc and dilute hydrochloric acid is carried out in two different conditions respectively. One reaction is carried out in a stoppered flask, which is regarded as a closed system. The other is carried out in a flask without a stopper, which is regarded as an open system. Which of the following statements concerning the two reactions are correct?

(1) The pressure increases in the closed system.

(2) The change in internal energy of the reaction in the open system is smaller than that in the closed system.

(3) The heat change of the reaction in the open system is smaller than that in the closed system.

A. (1) and (2) only

B. (1) and (3) only

C. (2) and (3) only

D. (1), (2) and (3)

21. Given that:

ΔH c [C2H2(g)] = x kJ mol1

ΔH c [H2(g)] = y kJ mol1

ΔH c [C2H6(g)] = z kJ mol1

Calculate the standard enthalpy change of the following reaction:

C2H2(g) + 2H2(g) C2H6(g)

A. x + 2y z

B. x + y z

C. 2xy z

D. z x 2y


22. Which of the following concerning the enthalpy change cycle shown below are correct?

(1) ΔH = ΔH 1 + ΔH 2 ΔH 3

(2) ΔH 1 = ΔH c [C2H4(g)]

(3) ΔH = ΔH c [C2H4(g)] + ΔH c [H2(g)] ΔH c [C2H6(g)]

A. (1) and (2) only

B. (1) and (3) only

C. (2) and (3) only

D. (1), (2) and (3)

Directions: Each question below (Questions 23 to 24) consists of two separate statements. Decide whether each of the two statements is true or false; if both are true, then decide whether or not the second statement is a correct explanation of the first statement. Then select one option from A to D according to the following table:

A. Both statements are true and the 2nd statement is a correct explanation of the 1st statement.

B. Both statements are true and 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.

1st statement 2nd statement

23. Ammonium chloride is not an electrolyte.

24. Polyethene can be softened by heating and hardened by cooling.

Ammonium chloride is made up of non-metals only.

Polyethene is an addition polymer.

END OF PART I


C2H4(g) + H2(g) ΔH

ΔH 2 ΔH 1

+ 3O2(g)+O2(g)

2CO2(g) + 3H2O(l)

ΔH 3

C2H6(g)+O2(g)

Part II

25. Which of the following exist in liquefied HF?

(1) Hydrogen bond

(2) Dispersion forces

(3) Covalent bond

A. (1) and (2) only

B. (1) and (3) only

C. (2) and (3) only

D. (1), (2) and (3)

26. Some marble chips are mixed with excess dilute hydrochloric acid in a stoppered conical flask. The flask is placed on an electronic balance to determine its mass. The mass of the reaction mixture is measured at regular time intervals. Which of the following graphs represents the rate of the reaction?

A. B.

C. D.

27. 20 cm3 of ethane (C2H6) are burned with 95 cm3 of oxygen to give carbon dioxide and water as the only products. What is volume of oxygen unreacted?(All volumes are measured at r.t.p.)

2C2H6(g) + 7O2(g) 4CO2(g) + 6H2O(l)

A. 20 cm3

B. 25 cm3

C. 55 cm3

D. 75 cm3


Time

Reading of the balance

Time


Time


Time


28. Consider the following equilibrium:

SO2Cl2(g) SO2(g) + Cl2(g)

In an experiment, 13.5 g of SO2Cl2(g) was introduced into a 4 dm3 container and allowed to reach equilibrium with SO2(g) and Cl2(g). At equilibrium, 0.069 mol of Cl2(g) was found in the reaction mixture. What is the equilibrium constant of the reaction?

(Relative atomic masses: S = 32.1, O = 16.0, Cl = 35.5)

A. 0.0384 mol dm3

B. 0.0768 mol dm3

C. 2.23 mol dm3

D. 3.34 mol dm3

29. Consider the following equilibrium system:

N2(g) + 3H2(g) 2NH3(g) ΔH = ve

Which of the following changes will occur if the temperature of the system increases at constant pressure?

(1) The equilibrium position will shift to the left.

(2) The value of Kc will increase.

(3) The yield of NH3(g) will decrease.

A. (1) and (2) only

B. (1) and (3) only

C. (2) and (3) only

D. (1), (2) and (3)

30. Which of the following compounds has/have a pair of geometrical isomers?

(1) CH3CH=CH2

(2) CH3OCCH=CHCOCH3

(3) CH2BrCH=CHCH2Cl

A. (1) only

B. (2) only

C. (1) and (3) only

D. (2) and (3) only


31. Which of the following statements concerning the compound below are correct?

(1) It has no reaction towards acidified potassium dichromate solution.

(2) It can react with lithium aluminium hydride in dry ether, followed by dilute hydrochloric acid to give

.

(3) It is optically inactive.

A. (1) and (2) only

B. (1) and (3) only

C. (2) and (3) only

D. (1), (2) and (3)

32. Which of the following products are formed when peanut oil is boiled with sodium hydroxide solution?

(1) Propane-1,2,3-triol

(2) Soapy detergents

(3) Ester

A. (1) and (2) only

B. (1) and (3) only

C. (2) and (3) only

D. (1), (2) and (3)

33. Which of the following comparisons about aluminium oxide and silicon dioxide is INCORRECT?

Al2O3 SiO2

A. White solid at 25C White solid at 25C

B. Giant ionic structure Giant covalent structure

C. Reacts slowly with water Do not react with water

D. Amphoteric oxide Acidic oxide


34. Which of the following statements concerning the reaction between KMnO4 and NaCl in alkaline solution is correct?

A. A brown precipitate is formed.

B. KMnO4 acts as a catalyst.

C. A brown gas is produced.

D. The solution turns pale pink.

Directions: Each question below (Questions 35 to 36) consists of two separate statements. Decide whether each of the two statements is true or false; if both are true, then decide whether or not the second statement is a correct explanation of the first statement. Then select one option from A to D according to the following table:

A. Both statements are true and the 2nd statement is a correct explanation of the 1st statement.

B. Both statements are true and 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.

1st statement 2nd statement

35. All hydrocarbons containing OH groups are soluble in water.

36. Although a catalyst will not be used up in a reaction, it is regarded as a reactant.

Methane and ethane are insoluble in water but methanol and ethanol are soluble in water.

A reaction is always speeded up when a catalyst is used in a reaction.

END OF PART IIEND OF SECTION A


BHONG KONG DIPLOMA OF SECONDARY EDUCATION

EXAMINATION

CHEMISTRY PAPER 1 (MOCK EXAMINATION)

SECTION B : Question-Answer Book B

This paper must be answered in English.

INSTRUCTIONS

(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 Book for Section A.

(3) This section consists of TWO parts, Part I and Part II. Part I carries 56 marks and Part II carries 28 marks. The marks to each question are indicated in brackets at the end of the question.

(4) Answer ALL questions in each part. 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) Supplementary answer sheets will be provided on request. Write your name, class and class number, fill in the question number. Tie them loosely but securely with a string INSIDE this Question-Answer Book.

(6) A Periodic Table is printed on the back of this Question-Answer Book. Atomic numbers and relative atomic masses of elements can be obtained from the Periodic Table.

Name

Class

Class no.

Question No.

Marks

1

2

3

4

5

6

7

8

9

10

11

12

Total


Set 1

PART I

Answer ALL questions. Write your answers in the spaces provided.

1. John dropped a piece of chalk into dilute hydrochloric acid. He found that gas bubbles appeared immediately.

(a) What is the chemical name for chalk?

(b) Write a word equation for the reaction occurred.

(c) What is the gas formed? Suggest a test for the gas.

(d) ‘A piece of chalk can be turned into a metal,’ a student claimed. Comment on his statement.

(6 marks)


Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

2. Consider the set-up as shown below.

(a) Explain why dilute hydrochloric acid is added to each side of the tube.

(b) Which colour slowly migrates towards the cathode? Which type of ions is responsible for this colour migration?

(c) Which colour slowly migrates towards the anode? Which type of ions is responsible for this colour migration?

(d) State the hazardous nature of dilute hydrochloric acid.

(e) If the carbon rods are replaced by wooden rods, what would happen?

(7 marks)


carbon rod

dilute hydrochloric acid

a gel containing copper(II) ions and dichromate ions

dilute hydrochloric acid

carbon rod

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

3. In an experiment to determine the concentration of ammonia solution, 25.0 cm3 of the ammonia solution was transferred into a conical flask and titrated against 0.1 M sulphuric acid. A few drops of indicator were added. The titration results are listed in the table below:

1 2 3 4Final reading (cm3) 15.90 16.70 18.40 18.50Initial reading (cm3) 0.00 1.50 3.10 3.40

(a) Which indicator is suitable for this titration?

(b) What will be the colour change of the indicator at the end point?

(c) (i) Calculate the reasonable average volume of sulphuric acid used.

(ii) Calculate the molarity of the ammonia solution.

(d) Name the salt formed and suggest ONE common use of the salt.

(8 marks)


Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

4. 5.8 g of a dry gaseous compound X (containing carbon and hydrogen only) were completely burnt in excess dry oxygen. The products were passed through a suitable drying apparatus containing anhydrous calcium chloride, and it was found that 9.0 g of water had been formed.

(a) Calculate the mass of hydrogen in 9.0 g of water.

(b) Calculate the mass of carbon in 5.8 g of X.

(c) Find the empirical formula of X.

(5 marks)


Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

5. Consider the following organic molecules:

A B C

(a) Give the IUPAC name of C.

(b) Which of the above organic molecules can undergo addition polymerization?

(c) For those molecule(s) which can undergo addition polymerization, write the equation for each reaction.

(d) Name the polymer made from C and give a daily use of the polymer.

(7 marks)


Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

6. Consider the simple chemical cell shown below.

(a) Which metal is more reactive, X or Y? Explain.

(b) Which is the positive pole, metal X or Y?

(c) (i) How can a salt bridge be prepared?

(ii) State the main functions of the salt bridge.

(5 marks)


metal X electrode

metal Y electrode

flow of electrons

sulphate solution of metal X

nitrate solution of metal Y

salt bridge

digital multimeter (as voltmeter)

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

7. In an experiment, 20.0 cm3 of 1.0 M HCl solution at 25C was added to 10.0 cm3 of 1.0 M Na2CO3 solution at 25C in an expanded polystyrene cup with stirring. The highest temperature recorded after mixing was 40.0C.

(a) Write the equation for the reaction between HCl(aq) and Na2CO3(aq).

(b) State TWO observations during the experiment.

(c) Calculate the enthalpy change of the reaction.(Assume that the specific heat capacity and the density of the reaction mixture are 4.2 J g1 K1 and 1.0 g cm3 respectively.)

(d) The theoretical value of the enthalpy change of the reaction is greater than the calculated value. Give TWO reasons for the difference.

(9 marks)


Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

8. Briefly describe some chemical methods of extracting metals from their ores, illustrating with an example in each case. State the relationship between the position of a metal in the reactivity series and its extraction method.

(9 marks)


Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

END OF PART I


Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

PART II

Answer ALL questions. Write your answers in the spaces provided.

9. A certain amount of solid ammonium hydrogensulphide is placed in a sealed flask already containing 0.60 mol dm–3 of ammonia gas at room temperature. It dissociates as follows:

NH4HS(s) H2S(g) + NH3(g)

At equilibrium, the concentration of ammonia gas is found to be 0.87 mol dm3.

(a) Write the expression for the equilibrium constant, Kc, for the above dissociation at room temperature.

(b) Calculate the equilibrium constant for the above dissociation at room temperature and state its unit.

(c) If the volume of the flask used was doubled, calculate the equilibrium concentration of ammonia gas.

(10 marks)


Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

10. Ethene can be converted to ethanol in a two-step synthesis.

(a) Draw the synthetic route with the corresponding intermediates, reagents and conditions required for each step.

(b) Ethanol obtained is further heated with propanoic acid to form an ester.(i) State the reagent and condition required for the esterification.

(ii) Identify the ester formed.

(c) The percentage yields for step 1, step 2 and step 3 are 70%, 67% and 42% respectively. What is the overall percentage yield?

(7 marks)


Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

11. An industrial chemist who works for a firm which manufactures ethyne (C2H2) discovers a very cheap way of producing ethyne. Unfortunately, the ethyne is contaminated with ethene. Unless the mixture contains at least 50% by volume of ethyne, it is useless. In order to determine the relative proportions of the two gases in the mixture, he exploded 10.0 cm3 of the mixture with 30.0 cm3 of oxygen. After absorbing the residual CO2 with KOH, the unreacted O2 occupied 2.0 cm3. Calculate the composition of the mixture by volume.

(4 marks)


Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

Ans

wer

s w

ritt

en in

the

mar

gins

wil

l not

be

mar

ked.

12. Answer the following questions:

(a) (i) Sulphur dioxide and sulphur trioxide are oxides of sulphur. Draw their structures.

(ii) Write a balanced equation for the conversion of sulphur dioxide to sulphur trioxide. Give the name of the catalyst used.

(iii) State the colour of SO2.

(b) (i) Draw the structure of dichlorine oxide.

(ii) State the colour of dichlorine oxide.

(7 marks)END OF PART II

END OF SECTION B


hkdse chem fx mock exam paper 1 2012 set 1 eng

Documents

aristo educational

porous nickel

relative atomic

dilute hydrochloric

undergo addition

secondary

colour slowly

sodium hydroxide