POK OI HOSPITAL TANG PUI KING MEMORIAL COLLEGE

FIRST TERM EXAMINATION (1996-1997)

F.5 Chemistry Paper 1

Class: 5 ____ Date:

Name: _________________ Time allowed: 90 minutes

Class Number: __________ (P.1-P.4 / 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. Answers ALL questions on the Answer Book provided. When answering questions in Section A, you are NOT to start each question on a new page.

4. The total score is 90 marks.

____________________________________________________________________________

Section A: Short Questions (36%)

1. i) Coal and petroleum are fossil fuels formed from different organisms.

a) What is coal formed from? (1%)

b) What is petroleum formed from? (1%)

ii) A new polymer is made by polymerizing the monomers ethane (E) and propene (P).

The polymer chain has the structure:

……----E-P-E-P-E-P----…..

a) Draw the structural formulae for the monomers. (1%)

b) Draw the repeating unit structural formula. (1%)

c) Is the polymer an addition or a condensation polymer? Explain. (2%)

d) Name TWO main types of plastics. (1%)

2. i) What is meant by the term ‘food additive’. (2%)

ii) Name THREE main types of food additives. (3%)

3. We have some tablets that contain antacids. Each tablet is a mixture of substances.

i) When a dilute acid is added to a tablet, a gas is produced.

a) Suggest the name of a compound in the tablet that can form the gas. (1%)

b) Name the gas formed. (1%)

c) Write an ionic equation for the reaction. (1%)

ii) When a tablet is placed in distilled water, the gas is also formed. What substances should be present in the tablets? (1%)

iii) Why does a dry tablet not react? (1%)

iv) What are antacids used for? (1%)

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. he following diagram shows a soap molecule:

CH₃-(CH₂)₁₆-C-O^-Na⁺ sodium octadecanoate

The above detergent molecule can be prepared from an ester of octadecanoic acid and sodium hydroxide in the school laboratory.

Name the chemical process for the preparation of soap and describe the experimental procedure in the laboratory for the preparing a soap ‘cake’ of this diagram. State the chemical hazard and precaution that should be taken. (9%)

5. Ammonia, sulphuric acid and fertilizers are important chemicals.

Should Hong Kong builds to make these substances. You should mention the factors of consideration for your decision making. (9%)

END OF SECTION A

Section B: Long Questions (54%)

6. I) The apparatus in the diagram was used for boiling a mixture of ethanoic acid, ethanol and concentrated sulphuric acid for about 10 minutes.

a) What is apparatus R called? (1%)

b) Where should tube P connect to? (1%)

c) What is the function of apparatus R? (1%)

d) Some solids are added to S to prevent frothing. What could be used for these

solids? (1%)

e) (1) Name the product formed in this reaction? (1%)

(2) What is its smell? Write the equation for the reaction. (2%)

f) What is the function of concentrated sulphuric acid in this reaction?(1%)

g) (1) Explain why the contents of the tube are poured into sodium hydrogencarbonate

solution before smelling them and (2%)

(2) Give the chemical equation concerned. (1%)

(II) The following chart shows some of the many chemicals that can be made from the

alkanes in the oil fraction naphtha:

a) Compound X is obtained during the cracking of naphtha.

(1) Give the name of X and write its structural formula. (1%)

(2) Octane is one of the alkanes in naphtha. Write an equation to show how X may be

formed. (1%)

b) (1) Draw a short length of the polymer Y. (1%)

(2) What is the name of Y? (1%)

c) Draw the structural formula for the monomer Z. (1%)

d) Name one use of

(1) polystryrene. (1%)

(2) Y. (1%)

7. I) Carefully study the following label of a bottle of sparking lemon juice and answer the questions that follow.

TPK

Ingredients: carbonated water, sugar, critic acid, artificial

flavouring, preservative, artificial colouring

(E121), saccharin

Notes: Keep cool and out of sunlight, pressurized

container, avoid damage to cap, drink within

three days of opening

Date of expiry: 20-1-1997

a) Is the bottle of ‘TPK’ fresh juice? Explain your answer. (1%)

b) What colour is the artificial colouring E121? (1%)

c) Why is the colouring E121 added to ‘TPK’? (1%)

d) Upon opening of the bottle, bubbles are giving off. What are those bubbles? (1%)

e) Why does the ‘TPK’ have to be kept cool and out of sunlight? (1%)

f) Using apparatus available in a school laboratory, design an experiment to measure the

volume of gas dissolved in a bottle of lemon juice. Draw a labeled diagram of the apparatus you would use. (3%)

II) The amount of chlorine in University swimming pool water should be between

0.5mg/dm³ and 1.0mg/dm³.

(1g = 1000mg)

(a)(1) Write the equation for the reaction that occurs when chlorine dissolves in water.

(1%)

(2) Which of the dissolved substances kill germs in water? (1%)

The bar chart shows the amounts of chlorine each day for a week.

b) On which TWO days were they NOT safe to use the swimming pool? (1%)

c) On which TWO days do you think they were hot and sunny? Explain. (2%)

d) What was the level of chlorine on Sunday morning? (1%)

e) The swimming pool contains 1,200,000dm³of water.

(1) What mass of chlorine is needed to bring the level back to 0.8mg/dm3 from the Sunday level? (2%)

(2) What volume of chlorine gas is needed at room temperature and pressure? (Relative atomic mass of chlorine=35.5, Molar volume of a gas at room conditions=24 dm³) (2%)

8. (I)Petroleum can be changed into ethanol by the following method:

a) Name the THREE stages. (3%)

b) Describe the purpose of each stage. (3%)

(II) The following drinks contain approximately equal amounts of pure ethanol.

a) Which has the greatest concentration of ethanol? (1%)

b) The beer and table wine are prepared by fermentation.

(1) What is meant by the term ‘fermentation’. (2%)

(2) What micro-organism is used in the fermentation process? (1%)

(3) What raw material is used to make beer? (1%)

(4) What raw material is used to make table wine? (1%)

c) (1) The ethanol in beer and wine does not exceed about 18%. Why not? (1%)

(2) Name the process that can increase the ethanol content to over 60%. (1%)

d) State TWO effects of heavy drinking of ethanol on

(1) the body. (2%)

(2) society. (2%)

End of Paper

POK OI HOSPITAL TANG PUI KING MEMORIAL COLLEGE

FIRST TERM EXAMINATION (1996-1997)

F.5 Chemistry Paper II

Class: 5 ____ Date:

Name: _________________ Time allowed: 60 minutes

Class Number: __________ (P.1-P.8 / 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 deduced for wrong answers.

___________________________________________________________________________

Multiple Choice Questions

1. Which of the following substances are the major fossil fuels?

(a) Natural gas

(b) Petroleum

(d) Town gas

A. (a) and (b) only

B. (c) and (d) only

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

D. All of them

2. Which of the following statements concerning coal are correct?

(a) Coal was formed by the underground compression of vegetable matter.

(b) Coal is a hard black shiny solid.

(d) Coal is a clean fuel and easy to mine.

A. (a) and (b) only.

B. (c) and (d) only.

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

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

Questions 3 and 4 refer to the experiment as illustrated below:

3. Which of the following is the name of the above experiment?

A. Cracking of crude oil

B. Reforming of crude oil

C. Fractional distillation of crude oil

D. Destructive distillation of crude oil

4. What is the purpose of placing the receiver tube in a beaker of cold water in collecting fractions?

A. To support the tube

B. To minimize the loss of water vapour

C. To cool the volatile substances formed

D. To prevent liquid spilling off

5. Ethane and butane

(a) contain hydrogen and carbon aoms only.

(b) Belong to the same homologous series.

A. (a) and (b) only.

B. (a) and (c) only.

C. (b) and (c) only.

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

6. The number of structural isomers having in the molecular formula C₅H₁₂ is

A. 3

B. 4

C. 5

D. 6

7. The IUPAC name of the compound shown below is

A. 3-chlor3-chlorobut-1-ene

B. 2-chlor3-chlorobut-3-ene

C. 3-chlor3-chlorobut-2-ene

D. 2-chlor3-chlorobut-2-ene

8. Which of the following structural formula represents a compound which is different from others?

9. The IUPAC name for the compound CH₃CH(OH)CH₂Br

A. 1-bromopropan-1-ol

B. 1-bromopropan-2-ol

C. 2-bromopropan-1-ol

D. 3-bromopropan-2-ol

10. Cracking of petroleum is a process which involves

(a) the breaking down of large molecules into small molecules.

(b) The production of both saturated and unsaturated products.

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

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

11. Which of the following is the most abundant constituent in Hong Kong Town gas?

A. hydrogen

B. carbon dioxide

C. methane

D. nitrogen

12. Which of the following precautions are necessary for the experiment?

(a) The first test-tube of gas collected should be discarded because it is mainly air.

(b) When collection of gas is over, the burner should be immediately removed to avoid sucking-back.

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

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

13. In an exothermic reaction,

(a) there is release of energy to the surrounding.

(b) The heat of reaction ΔH is negative.

A. (a) only

B. (b) only

C. (a) and (b) only

D. (b) and (c) only

14. Why can carbon dioxide be used to put out fires?

(a) Carbon dioxide, being denser than air, forms a ‘blanket’ over the fire and cuts out the air supply.

(b) Carbon dioxide itself does not burn and substances do not burn in it.

(c) Carbon dioxide ‘snow’ ejected out is subsequently changed to carbon dioxide gas in the fire, so it has a cooling effect.

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

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

15. What should be done to put out a raging forest fire?

(a) Use all the water fire extinguishers available.

(b) Cut a band of trees ahead of the path of the fire.

A. (b) and (c) only

B. (a) and (b) only

C. (a) and (c) only

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

16. Which of the following methods to help conserve energy?

(a) Use unleaded petrol

(b) Use less fuel

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

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

17. Which of the following concerning fire fighting is/are correct?

(a) In case of a fire due to gas leakage, the cutting off thing to do is to turn off the gas supply.

(b) Smaller fires are best put out by cutting off the air supply.

(d) Water from fire hose is used to remove heat

A. (a) and (b) only

B. (b) and (c) only

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

D. All of them

18. Which of the following gaseous pollutants when dissolved in rain water will make the rain acidic (acid rain)?

(a) SO₂

(b) NO₂

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

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

19. Which of the following are the environmental consequences of oil spillage?

(a) Oil floats on water and blocks oxygen supply to marine or aquatic livings.

(b) Oil is toxic

(d) Use of detergent to clean up the oil spillage will have secondary effect on marine or aquatic organisms.

A. (a) and (b) only

B. (c) and (d) only

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

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

20. There are many different kinds of plastics, some common ones include

(a) Perspex.

(b) Nylon.

(d) Propene

Which of the following alternatives is correct?

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

B. (a) and (c) only

C. (b) and (d) only

D. (d) only

21. Which of the following statements concerning a thermoplastic are correct?

(a) It softens on heating and hardens on cooling.

(b) It is a linear polymer, soluble in many organic solvents.

(d) All thermoplastic polymers are formed by the process of addition polymerization.

A. (a) and (b) only

B. (c) and (d) only

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

D. All of them

22. All of the following are synthetic polymers EXCEPT

A. nylon.

B. styrene.

C. polyvinyl chloride.

D. perspex.

23. Which of the following statements concerning polypropene is CORRECT?

A. Polypropene is a condensation polymer.

B. The repeating unit of polypropene is –[CH₂CH₂CH₂]-.

C. Polypropene is an electrical insulator.

D. Polypropene is a polymer of propane.

24. Which of the following compounds is likely to undergo addition polymerization?

A. HCOO-(CH₂)-NH₂

B. F₂C=CF₂

C. CH₃COCl

D. CH₃COOCH₃

25.

Which of the following monomers could polymerize to give the above polymer?

26. The percentage of carbon by mass in pentane is

(relative atomic masses: H=1, C=12)

A.85.7

B. 83.3

C. 38.3

D. 58.7

27. The process of using yeast to turn starch or sugar into ethanol is called

A. cracking

B. fermentation

C. fractional distillation

D. hydration

28. The group of organic compounds often added as artificial flavourings to food and drinks is

A. alkenes.

B. alkanols.

C. alkanoic acids.

D. esters.

29. In the industrial preparation of ethanol from ethane,

C₂H₄ (g) + H₂O (g) → C₂H₅OH (l)

Which of the following is usually employed as a catalyst?

A. concentrated sulphuric acid

B. platinum

C. phosphoric acid

D. iron

30. Which of the following methods is/are used for the industrial production of sulphur dioxide?

(a) adding dilute acid to a metal sulphite

(b) roasting metal sulphides in air

A. (a) and (b) only

B. (b) and (c) only

C. (c) only

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

31. Which of the following elements is needed only in very small amounts by plant crops?

A. phosphorus

B. nitrogen

C. sulphur

D. potassium

32. During the process of fermentation,

(a) carbon dioxide is produced.

(b) ethanol is produced.

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

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

33. Ammonium sulphate is an important fertilizer made by reacting aqueous ammonia and sulphuric acid. The following are the essential process involved in the laboratory preparation of ammonium sulphate:

(a) washing

(b) neutralization

(d) filtration

The correct sequence is

A. (b), (d), (c), (a)

B. (b), (c), (d), (a)

C. (c), (b), (a), (d)

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

34. Which of the following statements concerning ammonia is/are correct?

(a) It is used to manufacture nitric acid.

(b) Its aqueous solution is an important fertilizer.

A. (a) only

B. (c) only

C. (a) and (b) only

D. (b) and (c) only

35. Methylated spirit contains

(a) methanol

(b) ethanol

A. (a) and (b) only

B. (a) and (c) only

C. (b) and (c) only

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

36. Which of the following is/are the limitation(s) of soap?

(a) It does not clean in hard water.

(b) It does not clean in hot water.

A. (a) only

B. (b) and (c) only

C. (a) and (c) only

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

37. Which of the following can make a NPK fertilizer?

A. A mixture of NH₄NO₃ and (NH₄)₃PO₄

B. A mixture of KNO₃and (NH₄)3PO₄

C. A mixture of NH₄NO₃ and KNO₃

D. A mixture of Ca(NO₃)₂ and NH₄H₂PO₄

38. Many food labels list the additive monosodium glutamate (MSG), this food additive acts by

A. preserving the food.

B. Stimulating the taste buds.

C. Sweetening the food.

D. Emulsifying oil water in the food.

39. Some food additives have been given an ‘E number’. An ‘E number’ tell you

A. that the additive is guaranteed harmless.

B. that the additive is under test.

C. that the additive is beneficial to health.

D. that the additive has been approved by the European Community.

40. What types of additives might be used in making an orange squash drink?

(a) colourings

(b) preservatives

(d) sweeteners

A. (a) and (b) only

B. (c) and (d) only

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

D. All of them

41. Which of the following is a common active ingredient in antacids?

A. Magnesium hydroxide

B. Calcium oxide

C. Sodium hydroxide

D. Sodium carbonate

42. Which of the following drugs is additive?

A. codeine

B. paracetamol

C. morphine

D. aspirin

43. An analgesic is

A. a substance which reduces stomach acidity.

B. a substance which reduces pain.

C. a substance which makes a person feel calm.

D. a substance which makes a person feel sleepy.

44. Which of the following sets of combination is CORRECT?

(a) Aspirin

(b) Milk of magnesia

(d) Codeine

Antacid painkiller antibiotic cough medicine

A. (a) (b) (c) (d)

B. (b) (c) (d) (a)

C. (b) (a) (c) (d)

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

Directions: Each question below (Questions 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.

1 st statement

2 nd statement

45.

The Haber process is an important industrial process.

The Haber process manufactures nitric acid, which is an important industrial chemical.

46.

In the contact process, sulphur trioxide is added to concentrated sulphuric acid instead of water.

Dissolving sulphur trioxide in water is a highly exothermic reaction.

47.

Dry chlorine can bleach moist litmus paper.

Dry chlorine is acidic.

48.

Detergent can form an emulsion with grease.

Detergent can act as a wetting agent.

49.

Esterification is an addition reaction.

Esterification occurs when an ethanol molecule adds to an ethanoic acid molecules.

50.

Catalytic converters are used in vehicles which run on leaded petrol.

Catalytic converters can convert poisonous lead compounds into harmless compounds.

END OF PAPER