POK OI HOSPITAL TANG PUI KING MEMORIAL COLLEGE

MOCK EXAMINATION (1996-1997)

F.5 Chemistry Paper 1

Class: 5 ____                                            Date:                                                                  

Name: _________________                     Time allowed: 90 minutes                                                                  

Class Number: __________                       (P.1-P.6 / 20)

 

Instructions to students:

1.  The paper must be answered in English.

2.  There are TWO sections in this paper, section A (36%) and section B (54 %).

3.  Answer ALL questions in Section A and any THREE questions in Section B.

4.  ALL answers are written in the Answer Book provided. When answering questions in Section A, you are NOT to start each question on a new page.

5.  The total score is 90 marks.

__________________________________________________________________________

Section A: (Answer ALL question)

1.      (a) Consider the following hazard warning labels:

Choose TWO labels which should be displayed on a bottle of concentrated sulphuric acid. Explain your choice.

 (b) What would be observed when concentrated sulphuric acid is added dropwise to

      

(i)                  copper(II) sulphate pentahydrate crystals?

(ii)                Sucrose (cane sugar)?

 

Explain the observations and write appropriate equations.                              (6 marks)

 

2.      The electronic arrangements of four elements are given in the following table:

 

Element	Electronic Arrangement
A	2,4
B	2,6
C	2,8,2
D	2,8,7

 

(a)        A and B react to give gas X

(i)      Draw the electronic diagram (showing outermost shell electrons only) for gas X.

(ii)    Percentage of gas X is increasing in the Earth’s atmosphere. Give TWO reasons for the excessive production of gas X.

(b)       C and D react to give a solid Y.

 (i)  Draw the electronic diagram (showing outermost shell electrons only) for solid Y.

(ii)About 2 g of Y is dissolved in 1 dm³ of distilled water and electrolysed using carbon electrodes. Write the ionic equations for reactions taking place at the anode and cathode.

    (Relative atomic masses: C=24.3, D=35.5)                                (7 marks)

3.      The diagram below illustrates the cracking of medicinal paraffin.

            (a)    What is the function of the broken porous pot in the tube?

(b)   What are the conditions required for this process?

(c)    What we have finished collecting the gas, should we remove the burner first or should we remove the delivery tube from the water first? Explain your answer.

(d)   (i) What would be observed if the collected gas is shaken with bromine in tetrachloromethane?

(ii) Suggest a name for the gas collected.

(iii) Write an equation for the reaction that has occurred in (i)

                        (iv) Name the type of reaction that has occurred in (i).

                                                                                                                                (6 marks)

 

For questions 4 and 5, candidates are required to give paragraph-length answer. 3 of the marks for each of these two questions will be awarded for the effective communication of knowledge in Chemistry.

 

4.      Briefly describe an experiment, using the following apparatus and materials, to make simple cells and determine the positions of given metals in the electrochemical series. 

A voltmeter, 2 connecting wires with clip, sand paper, filter paper,

Sodium chloride solution, copper strip, magnesium strip, silver strip.

                                                                                                     (8 marks)

5.      Plastics are very useful yet they have many drawbacks. Suggest what are these drawbacks and the solution methods.                                                                                       (9 marks)

 

END OF SECTION A

  

Section B (Answer any THREE questions)

     6.      (a) A F.5 student set up the apparatus for titration as below:

      What THREE adjustments must be made in order to obtain accurate results?

                                                                                                  (3 marks) 

(b) Exactly 25 cm³ 0.10 M sodium carbonate solution is added to a conical flask. The

     carbonate solution is titrated against hydrochloric acid, using methyl orange as indicator, until the

   solution just change colour. The results are tabulated as follows: 

Volume of hydrochloric acid	1	2	3	4
Final reading, cm3	26.0	24.0	27.2	25.8
Initial reading, cm3	1.1	0.8	3.9	2.7

         (i)                  Write a piece of apparatus suitable for transferring exactly 25.0 cm³ of the carbonate solution.

(ii)                Write an equation for the reaction.

(iii)               Calculation the average volume of hydrochloric acid required to neutralize 25.0 cm³ of the carbonate solution.

(iv)              Calculate the molarity of the hydrochloric acid.

(7 marks)

(c) Two students set up the apparatus in the diagram below at room temperature. They were trying to study the best temperature for the reaction that occurred.

(i)                  What process occurs in the mixture?

(ii)                Name the TWO products of the process.

(iii)               How can you tell when the reaction in the mixture has stopped?

(iv)              What is the use of the balloon?

(v)                Why is a tight rubber band used?

(vi)              What can the students do to find the best temperature for the reaction?

(8 marks)

 

 

7.      (a) A student has done an experiment on the effect of light on chlorine water. He inverted a test tube over a beaker of chlorine water as shown in the following diagram. After an hour, a gas X was collected in the test tube.

       

(i)      What is gas X?

(ii) Suggest a chemical test for the gas.

(iii) Write chemical equation(s) for the decomposition of chlorine water.

        (iv) We usually store chlorine water in a dark coloured reagent bottle. Explain why.

                                                                                                                     (4 marks)

 

  (b)

 

    (i) Give the IUPAC name for vinyl chloride.

(ii) Write the equation for the formation of polyvinyl chloride (PVC) from vinyl

chloride.

           (iii) Give the type of polymerization for the preparation of polyvinyl chloride.

           (iv) Which type of moulding method is most suitable for the manufacture of PVC pipes?

      (v) A new polymer is made from polymerizing styrene and vinyl chloride.

                  (1) Draw one of the structures of the repeating unit for this new polymer.

                  (2) Suggest whether this new polymer is thermoplastic or thermosetting plastics.

                     Explain briefly.          

                                                                                                                  (7 marks) 

(c) The following is a part of the periodic table:

	Group
	I	II	III	IV	V	VI	VII	VIII
Second Period				a			b
Third Period	c		d			e	f	g

Referring to the letters indicated in the above table, answer the following questions: 

(i)                  How are the elements arranged in the Periodic Table?

(ii)                What is the name for the family of elements of which c is member?

(iii)               What is the name for the family of elements of which b and f are members

(iv)              In what way are the electronic arrangements of the atoms of elements b and f

(1)   Similar to each other?

(2)   Different from each other?

(v)                Classify elements a to g into metals, metalloid and non-metals.

(7 marks) 

8.      (a) Natural silicon consists of a mixture of three isotopes as following table:

            Calculate the atomic mass of silicon.                                                                                          (2 marks)

(b)       The container of the dry cell, which also serves as one of the electrodes, is made of zinc. The container is lined with porous paper, which separates the metal from the material within the cell. A graphite rob is placed at the center and used as the other electrode. The space between the graphite rod and the zinc container is filled with a moist mixture of ammonium chloride, manganese(IV) oxide, zinc chloride, and carbon powder.

 

(i)                  (1) Which one is the positive electrode?

(2) Write an equation to show the reaction at the positive electrode.

(ii)                (1) Which one is the negative electrode?

(2) Write an equation to show the reaction at the negative electrode.

(iii)               Give the use of carbon powder in the core around the graphite rod.

(iv)              When the cell is used for several hours, it appears to be run down. After standing idle for some time, the cell seems to recover and can continue supply current. Explain why.

(v)                Explain why the zinc case of a used cell is thinner than that of a new cell.

(vi)              State two advantages of using dry cells in daily life.

(8 marks) 

            (c)

(i)                  Name the above process.

(ii)                Hydrogen is obtained from methane and steam. Describe with equation, how the hydrogen is produced.

(iii)               Name the catalyst used in the reaction chamber.

(iv)              Write an equation for the reaction in the reaction chamber.

(v)                What is the function of the heat exchanger?

(vi)              What is the purpose of adding water into the absorption tower?

(vii)             Name the product Q.

(viii)           Suggest a domestic use of ammonia.

(8 marks)

 

9.      (a) In an experiment to prepare copper (II) sulphate crystals, copper(II) oxide powder was added to a colourless liquid P until no more would dissolve. The resulting solution Q, after removing the excess copper (II) oxide, was concentrated to solution R. After leaving this solution for several days, crystals of copper (II) sulphate began to separate out. They were separated from the solution by filtration, the filtrate being called S. 

(i)                  What is the liquid P?

(ii)                What are the colours of

(1)   copper (II) oxide, and

(2)   solution R?

(iii)               Draw a labeled diagram to show how you would concentrate solution Q.

(iv)              Which of the solutions P, Q, R and S is a saturated solution of copper (II) sulphate?

(v)                Consider the three changes which took place: 

P to Q,     Q to R, R to S

                                    Which of these changes can be considered as

(1)   physical changes,

(2)   chemical changed. 

(vi)              Describe briefly any differences that would be observed if the copper (II) sulphate solution were cooled

(1)   slowly, and

(2)   rapidly.

(9 marks)

 

(b) The diagram below shows how a student set up the electrolysis of molten

   lead (II) bromine and dilute sodium chloride solution.

 

(i)                  In voltmeter I, which is the cathode?

(ii)                What do you expect to see around the electrodes P and Q.

(iii)               Write ionic equations for reactions occurring at the electrodes P and Q.

(iv)              What is the product at electrode R? Write ionic equation for the reaction at electrode R.

(v)                What do you expect to see when a few drops of universal indicator solution is added to electrode S? Explain briefly.

(9 marks)

 

End of Paper

 

 POK OI HOSPITAL TANG PUI KING MEMORIAL COLLEGE

MOCK EXAMINATION ( 1996-1997 )

F5  Chemistry Paper II

 

Class: ____                                      Date; 24-3-1997

Name: _________                          Time allowed: 60 minutes

Class No.:_____                            (P.l-P.9/20)

Instructions to students:

1. There are 50 questions in this paper. The total score Is 60 marks.

2. Answer ALL questions. All the answers should be marked on the Answer Sheet.

3. Note that you may only mark ONE answer to each question. Two or more answers will score NO MARKS.

4. All questions carry equal marks. No marks will be deducted for wrong answers.

__________________________________________________________________________

There are 50 questions in this paper.

1. An ionic compound has the formula X₂Y₃. The ions present in me compound are

A.  X²⁺ ions and Y^3- ions.

B.  X³⁺ ions and Y^2- ions.

C.  Y³⁺ ions and X²⁺ions.

D.  Y²⁺ ions and X^3- ions.

2. Elements in the same group of the Periodic Table have the same

(a) electronic configuration.

(b) number of electrons in the outermost shell.

(c) number of neutrons.

Which of the following is/ are correct?

A.     (b) only           

B.     (c) only       

C.     (b) and (c)only

D.     (a), (b) and (c)      

3. In going from left to right, elements in the third row (Na to Ar) of the Periodic Table show

(a) a gradual increase in their tendency to gain electrons.

(b) a gradual increase in melting and boiling points.

(c) a gradual increase in atomic volume.

 Which of the following is/ are correct?

A. (a) only

B. (a) and (b) only

C. (a) and (c) only

D. (b) and (c) only

4. Which of the following concerning alkali metals are correct?

(a) They all have similar chemical properties.

(b) Each member has one electron in the outermost shell.

(c) The reactivity increases down the Group.

(d) The relative atomic mass of each successive member increases by 8.

A.     (a) and (b) only

B.     (b) and (c) only

C.     (a), (b) and (c) only

D.     (a), (b), (c) and (d)

 

5. Which of the following are polar covalent molecules?

(a) CH₄

(b) NH₃

(c) H₂O

(d) HCl

A. (a) and (c) only

B. (b) and (d) only

C. (b) and (c) only

D. (b), (c) and (d) only

6. Which alloy contain copper ?

(a) brass

(b) bronze

(c) coin metal

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

D. (a), (b) and (c)

7. Metals are good conductors of heat and electricity because they

A. have shiny surfaces.

B. consist of electrons.

C. have free-moving electrons.

D. have electrons that do not from bonds.

 

8. An iron nail is covered with water. Which of the following procedures would NOT increase the rate at which the iron nail corrodes ?

 

A.  Adding some sodium sulphate to the water.

B.  Attaching a copper wire to the iron nail

C.  Passing carbon dioxide through the water

D.  Adding some glucose to the water

9. Which of the following chemical properties is/ are common to all metals 7

(a) They are electron donors.

(b) They displace hydrogen from all dilute acids.

(c) They form basic oxides.

A. (a) only

B. (a) and (b) only

C. (a) and (c) only

D. (b) and (c) only

 

10. Which of the following general methods for making salts can best be used to prepare lead (II) carbonate?

   A. mixing metal with dilute acid

   B. mixing metal oxide with dilute acid

   C. mixing alkali with acid

   D. precipitation 

11. Which type of cell is most suitable for use in a hearing aid ?

A. a zinc - carbon cell

B. a silver oxide cell

C. a nickel - cadmium cell

D. an alkaline manganese cell

12. Which of the following outlined below is most likely to result in me production of magnesium?

A. Electrolysis of an aqueous solution of magnesium chloride

B. The passing of hydrogen over heated magnesium oxide

C. Electrolysis of molten magnesium chloride

  D. The addition of calcium to an aqueous solution of magnesium chloride

13. Anodized aluminium is

A. aluminium which has had the oxide layer removed.

B. aluminium which has had its oxide layer thickened in an electrolytic cell

C. ahimuuum which has been electrolytically purified.

D. ahimumnn which has been electrolytically plated with another metal.

14. Dilute sulphuric acid (2M) is dropped on to a mixture of magnesium and magnesium carbonate. Which of me following would be the most likely composition of the gas evolved?

A. carbon dioxide only

B. hydrogen only

C. hydrogen and carbon dioxide

D. carbon dioxide and sulphur dioxide

15. In which of me following reactions is me hydrogen ion an oxidizing agent ?

A. Mg + 2HCl ————> MgCl2 + H₂

B. NaOH + HNO3 ————> NaNO3 + H2O

C. CuCO3 + H2SO4 ———> CuSO4 + H2O + CO2

D. CH3COONa + HCl ——> NaCl + CH3COOH

16. The pH of a given solution is 5. Which of the following, when added to me given solution, would increase its pH ?

A. water

B. 1 M hydrochloric add

C. sodium chloride crystals D. 1 M ethanoic acid

　

17. Which of me following do NOT turn dry red litmus paper blue ?

(a) solid potassium hydroxide

(b) ammonia gas

(c) sodium carbonate solution

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

D. (a),(b) and (c)

18. Which of the following common household substances have a pH value greater than 7 ?

(a) 5% soap solution

(b) 7-up soft drink

(c) Philips' Milk of Magnesia suspension

(d) Brine

A. (a) and (c) only

B. (b) and (d) only

C. (a), (c) and (d) only

D. (b), (c) and (d) only

19. Which of the following processes may involve neutralization ?

(a) Soil pH control

(b) Fertilizer manufacture

(c) Industrial waste treatment

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

D. (a),(b)and(c)

20. In the reaction 2C(s) + O₂(g) ——> 2 CO(g), what mass of carbon is required to form 2.4 dm³ of CO at room temperature and pressure ?

(relative atomic masses : C = 12, O = 16)

A. 0.6 g

B. 1.2 g

C. 6.0 g

D. 12.0 g

21. The IUPAC name of CH₃CH=C(CH₃)₂ is

A. 2, 2 - dimethylprop-1-ene

B. 3 - methylbut-1-ene

C. 3 - methylbut - 2 - ene

D. 2 - methylbut - 2-ene

22. Which of the following reactions is/ are endothermic ?

(a) Cracking of medicinal paraffin

(b) Melting of lead (II) chloride

(c) Thermal decomposition of sodium chloride

(d) Burning of methane in air

A. (a), (b) and (c) only

B. (a) and (b) only

C. (b) and (d) only

D. (d) only

23. Which of me following pollutants can be cut down by installing catalytic converters to motor can?

(a) Nitrogen oxides

(b) carbon monoxide

(c) Sulpur dioxide

(d) Unburnt hydrocarbons

A. (a) and (b) only

B. (c) and (d) only

C. (a), (b) and (d) only

D. (a), (b), (c) and (d)

24. Petroleum can be refined to give many useful products. These include

(a) fuels.

(b) lubricating oils and waxes.

(c) bitumen.       

Which of the following is correct ?

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

D. (a), (b) and (c)

25. Zinc and copper are connected to form a chemical cell shown below:

Which of the following statements are correct ?

(a) The copper electrode increases in mass.

(b) Electrons flow from copper to zinc through the external circuit.

(c) The blue colour of the copper (II) sulphate solution fades.

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

D. (a),(b)and(c)

26. Which of me following is/ are thermoplastics ?

   (a) Urea-methanal

    (b) Polystyrene

    (c) Nylon

     (d) Perspex

A. (a) only

B. (b) and (c) only

C. (a) and (d) only

D. (b), (c) and (d) only

27. Which of me following types of reaction can ethene undergo ?

(a) Combustion

(b) Addition    

(c) Polymerization

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

D. (a), (b) and (c)

2    28.The flow diagram below shows how polythene may be made from petroleum.

What are me processes (1), (2) and (3) ?

      1                                       2                                  3          

   A. Fractional distillation       Cracking              Polymerization

   B. Fractional distillation       Distillation            Cracking

   C. Cracking                         Distillation            Polymerization

   D. Cracking                    Depolymerization       Distillation

 

      29. Which of the following are the uses of alcohols ?

    (a) As solvents

     (b) As fuels

    (c) To make alcoholic drinks

     (d) To make other useful organic compounds such as alkanoic acids and esters

A. (a) and (b) only          

B. (c) and (d) only

C. (a), (b) and (c) only

D. (a), (b), (c) and (d)

      30. The ionic 'head' is

     (a) hydrophobic.

     (b) usually an anionic group.

     (c) oil-repelling.

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

D. (a), (b) and(c)

      31. Ammonia cannot be produced by

     (a) healing ammonium sulphate with hydrochloric acid.      

     (b) heating ammonium sulphate with sodium hydroxide.

     (c) combining hydrogen and nitrogen in the presence of a catalyst at room temperature

A. (a) only

B. (b) only

C. (a) and (c) only

D. (b) and (c) only

      32. Which of the following descriptions about me functions of substances added to soil are

    correct?

     (a) Ammonium nitrate replenishes the essential minerals used up by vegetation.

     (b) Calcium oxide supplies calcium ions for the healthy growth of vegetation.

     (c) Slaked lime neutralises acidic soil.

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

D. (a), (b) and (c)

　

Directions: Questions 33 - 34 refer to the manufacture of sulphuric acid by the contact

        process, which can be represented by the following flow diagram:

　

            S —stage 1—> SO₂—stage 2 -> SO₃ —stage 3—> H₂S₂O₇ -stage 4--->H₂SO₄

     33. Which stage involves the greatest change in the oxidation number of sulphur ?

A. Stage 1

B. Stage 2

C. Stage 3

D. Stage 4

       34. Which stage involves the presence of catalyst ?

A. Stage 1

B. Stage 2

C. Stage 3

D. Stage 4

       35. Ammonia is oxidised according to the equation shown below:

4NH₃(g) + 3O₂(g) ——> 2N₂(g) + 6H₂O(l)

    What volume of oxygen is required for oxidising 240 cm³ of ammonia under me same conditions of temperature    

     and pressure 7

A. 120cm³

B. 160cm³

C. 180cm³

D. 200cm³

       36. Chlorine is used

(a) to manufacture bleaching agent.

(b) as a raw material for me production of hydrochloric acid.

(c) in the liberation of bromine from potassium bromide.

(d) in the manufacture of sodium chloride.                              

A. (a) and (c) only

B. (b) and (d) only

C. (a), (b) and (c) only

D. (a), (b), (c) and (d)

        37. Which of me following is not a natural flavouring.?

         A. sugar

   B. pepper

   C. synthetic ester

   D. vinegar

         38. Which of the following combinations is incorrect ?

Type of additive    First digit of E number            

A.  preservative                   2

B.  colouring                       1

C.  emulsifier                      3

D.  flavouring                      4

 

          39. Sulphur dioxide can preserve food because

    (a) it can act as anti-oxidant.

    (b) of its toxicity towards bacteria.

    (c) it can dehydrate bacteria by osmosis.

    A. (a) only

    B.(a) and (b) only

    C. (b) and (c) only

    D. (a), (b) and (c)

            40. An excess of silver nitrate solution is added to a solution of sodium chloride, and a white precipitate is   

                formed. After filtering off the precipitate, which of the following reagents in solution would NOT give a

                precipitate when added to the filtrate ?

A. Barium chloride

B. Potassium nitrate

C. Calcium hydroxide

D. sodium bromide.

              41. Crude oil can be separated into various fractions by fractional distillation because its constituents have

                    different

A. boiling points.

B. melting points.

C. densities.

D. viscosities.

              42. How many atoms will be present in 12 dm³ of gaseous fluorine at room temperature and pressure?

A. 1.5x 10²³

B. 3x10²³

C. 6x10²³

D. 1.2 xl0²³

              43. A cation X³⁺ possesses 18 electrons. An atom of X contains

A. 15 protons.

B. 18 protons.

C. 21 protons.

D. 24 protons.

               44. Which of me following pairs has the same electronic configuration ?

A. Na⁺ and Al ²⁺

B. O^2- and Na⁺

C. S^2- and Na⁺

D. Cl^- and K

Directions: Each question below (Question Nos.45 to 50) 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 but the 2nd statement is NOT a correct explanation of The 1st statement.  C.        Only one statement is true while the other is false.         D.  Both statements are false.