HKCE PAST PAPERS 86-94/SECTION 6/MC/PAGE 1
SECTION 6
IMPORTANT PRODUCTS FROM PETROLEUM
1986 23.
Which of the following represents the correct structural formulae for X and Y in the above equation?
25. Which of the following combinations correctly represents the monomer, repeating unit and structural formula of polypropene?
46. Which of the following statements are true for a ‘soapless’ detergent? (1) It does not form any bubbles when shaken with water. (2) Its molecule usually has a hydrophilic end. (3) It is usually synthesized from by-products of the petroleum refining industry. A (1) & (2) only B (1) & (3) only C (2) & (3) only D (1), (2) & (3) 1987
HKCE PAST PAPERS 86-94/SECTION 6/MC/PAGE 2
H
21. Which of the following statements concerning soapless detergents is correct? A They are biodegradable. B They form a scum with sea-water. C They have a hydrophilic end and a hydrophobic end. D They are made by the saponification of vegetable oils. 22. Which of the following statements concerning nylon is correct? A It is an addition polymer. B It melts in boiling water. C It has a low tensile strength. O H D
It contains the
C N
H C
C H
D
The structure of polystyrene is
n
1988 27.
linkage.
27. The following is a series of reactions starting from ethanol: Na2CO3(aq) A ethanol reagent → P → CO2(g) + Q Which of the following correctly describes the nature of reagent A and the product Q? Reagent A Product Q A dehydrating agent ethene B dehydrating agent ethane C oxidizing agent sodium ethanoate D oxidizing agent ethanoic acid 50. Which of the following statements concerning polystyrene is INCORRECT? A Polystyrene is an electrical insulator. B Polystyrene can be used as a heat insulator. C Expanded polystyrene (Styrofoam) is widely used as a packaging material.
Ethanol and propanoic acid are heated together as shown in the diagram. The main purpose of using the condenser is to
HKCE PAST PAPERS 86-94/SECTION 6/MC/PAGE 3
A B C D
prevent ethanol from catching fire. prevent loss of the reactants. purify the product. separate ethanol from propanoic acid.
30. Which of the following equations represent a dehydration reaction? A Cu + 2 H2SO4 → CuSO4 + SO2 + 2 H2O B (NH4)2CO3 → 2 NH3 + CO2 + H2O C C2H5OH → C2H4 + H2O D CuSO4 + 5 H2O → CuSO4.5H2O Direction: Questions 43 and 44 refer to the possible structural formulae of THREE detergents shown below:
D
II & III only
45. Which of the following are condensation polymers? (1) urea-methanal (2) perspex (3) nylon 6,6 (4) polystyrene A (1) & (2) only B (1) & (3) only C (1), (2) & (4) only D (2), (3) & (4) only 46. Which of the following properties make plastics useful in daily life? (1) They are chemically inert. (2) They can be moulded to any shape. (3) They are heat resistant. A (1) & (2) only B (1) & (3) only C (2) & (3) only D (1), (2) & (3) 1989
43. Which water? A B C D
of the three detergents can function normally in both hard and soft I only III only I & II only II & III only
44. Which of the three detergents would cause the more serious pollution problems? A I only B III only C I & II only
22. Which of the following pairs of products is formed when ethyl ethanoate is refluxed with sodium hydroxide solution? A CH3COOH and C2H5ONa B CH3COONa and C2H5OH C CH3OH and C2H5COONa D CH3ONa and C2H5COOH 23. The structure of a soap molecule can be represented as follows: O C
ONa
HKCE PAST PAPERS 86-94/SECTION 6/MC/PAGE 4
Which part of this structure makes the soap molecule hydrophobic? A. O C
B. C. Na+
-
O
O
D.
C
44. Which of the following types of reaction can propene undergo? (1) hydrogenation (2) polymerization (3) combustion A (1) & (2) only B (1) & (3) only C (2) & (3) only D (1), (2) & (3) 45. Which of the following statements concerning soapless detergents are correct? (1) They do not form scum with calcium ions. (2) They are made from by-products of the petroleum industry. (3) They are all biodegradable. A (1) & (2) only B (1) & (3) only C (2) & (3) only D (1), (2) & (3) 1990 36. Which of the following tests can be used to distinguish between ethane and ethene? (1) burning the gas in air (2) bubbling the gas through bromine in tetrachloromethane
(3) bubbling the gas through acidified potassium permanganate solution A (1) & (2) only B (1) & (3) only C (2) & (3) only D (1), (2) & (3) 37. Clothes stained with grease can be cleaned by detergents because detergents can (1) decrease the surface tension of water. (2) dissolve in both water and grease. (3) emulsify greasy particles. Which of the following combinations is correct? A (1) & (2) only B (1) & (3) only C (2) & (3) only D (1), (2) & (3) 38. Which of the following statements concerning the production of soap from vegetable oils and sodium hydroxide solution is/are correct? (1) Sodium hydroxide acts as a catalyst. (2) Glycerol is formed at the end of the reaction. (3) The reaction between vegetable oils and sodium hydroxide solution is reversible. A (1) only B (2) only C (1) & (3) only D (2) & (3) only 39. A glass of sweet wine is left on a dining table. After two days, the wine becomes sour. Which of the following type of reactions accounts for this change? A oxidation B hydrolysis C fermentation D esterification
HKCE PAST PAPERS 86-94/SECTION 6/MC/PAGE 5
40. When a piece of plastic X is placed on a hot plate at about 200 °C, it starts to soften. When X is placed in a flame, it burns with a yellow flame and liberates smoke with a vinegar smell. X is likely to be A polythene. B polyvinyl chloride. C cellulose ethanoate. D urea methanal. 41. Which of the following polymers is/are made by condensation polymerization?
A B C D
(1) only (3) only (1) & (2) only (2) & (3) only
1991 22. Propene reacts with acidified potassium permanganate solution to form A CH3CH2CH2OH. B CH3CH(OH)CH3. C CH3CH(OH)CH2OH. D CH2OHCH(OH)CH2OH. 26. Teflon, a polymer used for coating non-stick cooking utensils, has the structure given below:
...
F
F
F
F
F
F
C
C
C
C
C
C
F
F
F
F
F
F
...
Which of the following is the monomer for Teflon? A 1,2-difluoroethane B 1,2-difluoroethene C 1,1,2,2-tetrafluoroethane D 1,1,2,2-tetrafluoroethene 27. A sample of polymer gives acid fumes on strong heating. The polymer is probably A nylon. B polypropene. C polystyrene. D polyvinyl chloride. 33. Which of the following statement is/are true for soapless detergents? (1) All soapless detergents are not biodegradable. (2) Soapless detergents form a scum with sea water. (3) Soapless detergents are mainly manufactured from products of the petroleum industry. A (1) only B (3) only C (1) & (2) only D (2) & (3) only 40. Which of the following compounds would react with each other to form a condensation polymer?
HKCE PAST PAPERS 86-94/SECTION 6/MC/PAGE 6
A B C D
(1) & (2) (1) & (3) (2) & (4) (3) & (4)
1992
Direction: Questions 22 and 23 refer to the making of soap as represented by the following reaction:
20. Which of the following compounds does NOT react with propan-1-ol? A sodium B bromine water C acidified potassium permanganate solution D ethanoic acid 21. When 2-methylpropene reacts with bromine in tetrachloromethane, the product is
22. What is/are the function(s) of the sodium hydroxide in this reaction? (1) to act as a catalyst (2) to neutralize the acid formed during the reaction (3) to lower the solubility of soap in water so as to salt out the soap A (1) only B (1) & (2) only C (1) & (3) only D (2) & (3) only [IGNORE THIS QUESTION]
HKCE PAST PAPERS 86-94/SECTION 6/MC/PAGE 7
23. Soap has a hydrophilic head and a hydrophobic tail. Which of the following combinations is correct? hydrophilic head hydrophobic tail A Na+ CH3(CH2)16 B - COO CH3(CH2)16 C Na+ CH3(CH2)16COOD CH3(CH2)16COO Na+
A B C D
(1) only (2) only (1) & (3) only (2) & (3) only
1993 Direction: Questions 30 and 31 refer to the following experiment:
O 25. The polymer formed by H2N-(CH2)6-NH2 andHO C H A B C D
N (CH2)6 has a formula of is a thermosetting plastic. has cross-linkages. burns with a floral smell.
O (CH2)4
H O N C
C OH O
(CH2)4
C
A mixture of methyl propanoate and sulphuric acid was allowed to react by heating under reflux for some time until equilibrium was reached. The resulting mixture M was then transferred to flask Y and heated as shown below:
n
41. A compound, C2H4O2, reacts with ethanol in the presence of concentrated sulphuric acid to form a product with a fruity smell. Which of the following statements about this compound is/are correct? (1) It can liberate carbon dioxide from sodium carbonate solution. (2) It can decolorize acidified potassium permanganate solution. (3) Its aqueous solution is an electrolyte. A (3) only B (1) & (2) only C (1) & (3) only D (1), (2) & (3) 43. Which of the following polymers is/are NOT suitable for making a container for boiling water? (1) perspex (2) urea-methanal (3) polyvinyl chloride
30. What is the function of the piece of apparatus labelled X? A to condense the products in M B to separate the products in M
HKCE PAST PAPERS 86-94/SECTION 6/MC/PAGE 8
C D
to prevent the loss of the products in M due to evaporation to prevent the loss of the reactants in M due to evaporation
31. The first fraction of the distillate collected in flask Z is mainly A methanol. B propan-1-ol. C methanoic acid. D propanoic acid. 32. Which of the following substances can react with propene? (1) concentrated sodium hydroxide solution (2) acidified potassium permanganate solution (3) ethanol A (1) only B (2) only C (1) & (3) only D (2) & (3) only 34. When concentrated sulphuric acid is added dropwise to a solution containing urea and methanal in a test tube with shaking, a white solid can be formed. Which of the following statements about this experiment is/are correct? (1) The reaction involved is condensation polymerization. (2) Concentrated sulphuric acid acts as an oxidizing agent. (3) The white solid is a thermoplastic substance. A (1) only B (3) only C (1) & (2) only D (2) & (3) only 35. A polymer has the following structure: Cl H Cl H Cl H ...
C
C
C
C
C
C
H Cl H Cl H Cl
...
Its monomer is A chloroethene. B 1,1-dichloroethane. C 1,2-dichloroethene. D 1,2-dichloroethane. 1994 19. Which of the following substances can turn an acidified solution of potassium permanganate colourless? A ethane B ethanol C ethanoic acid D ethyl ethanoate 20. X is a synthetic polymer. On gentle heating, it softens and chars. On strong heating, it burns with an acidic smell. X is probably A polypropene. B polystyrene. C polyvinyl chloride. D perspex.
Direction: Questions 24 and 25 refer to the structural formulae of the following three detergents:
HKCE PAST PAPERS 86-94/SECTION 6/MC/PAGE 9
H
H C
CH3CH2
C H
Which of the following statements about this compound are correct? (1) It can decolorize bromine water. (2) It can be polymerized. (3) It can burn in air. A (1) & (2) only B (1) & (3) only C (2) & (3) only D (1), (2) & (3)
24. Which of the following statements concerning these detergents is correct? A The hydrocarbon tail of detergent III is hydrophilic. B Both detergents I and II form scum with seawater. C Detergent III causes more serious pollution problems than detergent I when discharged into rivers. D Both detergents II and III are made from fats. 25. Which of the above is/are soapless detergent(s)? A detergent I only B detergent III only C detergents I and II only D detergents II and III only
41. A compound has the following structure:
42. Which of the following substances can be fermented to give an alcoholic drink? (1) grapes (2) wheat (3) potatoes A (1) & (2) only B (1) & (3) only C (2) & (3) only D (1), (2) & (3)