d. rubidium has a higher reactivity with water than sodium.chemistryhk.com/chemmock/set 6-12/set 8...

2006-ME-CHEM 2 -1-

2006-ME-CHEM 2 -2- Go on to the next page

There are 30 questions in Section A and 20 questions in Section B.

Atomic numbers and relative atomic masses of elements can be obtained from

the Periodic Table printed on page 1. Section A 1. A compound formed from the hydrogen, carbon and nitrogen has the following

electronic structure:

H C N

(Only electrons in the outermost shells are shown.) How many bond pair(s) are there in the compound? A. 2 B. 3 C. 4 D. 5 2. The following hazard warning labels are displayed on the reagent bottle of a

chemical.

What information about this chemical can be obtained from the labels?

A. It is corrosive and oxidizing. B. It is toxic and oxidizing. C. It is corrosive and flammable. D. It is carcinogenic and flammable.


3. Which of the following can conduct an electric current? A. Tetrachloromethane B. Brine C. Glucose D. Marble 4. Both sodium and rubidium (Rb) are Group I elements. Which of the following

statements about sodium and rubidium is incorrect? A. Rubidium has a higher reducing power than sodium. B. Rubidium has a higher tendency to form cations than sodium. C. Rubidium has a higher melting point than sodium. D. Rubidium has a higher reactivity with water than sodium. 5. What is the percentage by mass of water in hydrated calcium sulphate

CaSO4 2H2O? A. 10.5 % B. 13.2 % C. 20.9 % D. 26.5 % 6. Which of the following may form a white precipitate with excess amount of

sodium hydroxide solution? A. Lead(II) nitrate solution B. Potassium nitrate solution C. Copper(II) nitrate solution D. Magnesium nitrate solution


7. Which of the following are the functions of detergents which increase the cleaning power of water to remove dirt?

(1) Reduce the surface tension of water. (2) Act as emulsifying agent. (3) Produce foam during washing. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) 8. Which of the following correctly describes the sequence of procedures to

separate sand, salt and water from a mixture of sand and salt solution? A. filtration, evaporation B. filtration, distillation C. crystallisation, filtration D. crystallisation, filtration, distillation 9. Which of the following has the lowest boiling point?

A. ethane B. butane C. ethanoic acid D. butanoic acid


10. Which of the following is a non-renewable energy source?

A. Nuclear energy B. Wind energy C. Solar energy D. Hydroelectric energy

11. What is the systematic name of the following hydrocarbon?

C C C H

H

H

CH3 CH3

CH3

H

H A. 1,2,2-trimethylpropane B. 2,2,3-trimethylpropane C. 2,2-dimethylbutane D. 3,3-dimethylbutane 12. Which of the following changes is NOT a redox reaction? A. HNO3 + NH3 → NH4NO3 B. 2HNO3 + SO2 → H2SO4 + 2NO2 C. 4HNO3 + 3Fe(NO3)2 → 3Fe(NO3)3 + NO + 2H2O D. 4HNO3 → 2H2O + 4NO2 + O2 13. Which of the following flame colours observed in flame tests is correct? Metal Flame colour A. Calcium Golden yellow B. Iron Bluish green C. Sodium Very bright white light D. Potassium Lilac


14. Which of the following are the advantages of using plastics over using metals in

making a helmet for a soldier? (1) Plastics do not conduct electricity. (2) Plastics do not corrode easily. (3) Low density. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) 15. An oxide of lead, X, contains 90.6% of lead by mass. What is the empirical

formula of X? A. PbO B. Pb3O4 C. Pb4O5 D. Pb4O6 16. Large amount of sulphuric acid leaked into river from an acid tanker after an

accident. Which of the following substances should be used to treat the spilled acid?

(1) Sodium hydroxide (2) Calcium oxide (3) Sodium hypochlorite A. (1) only B. (2) only C. (1) and (2) only D. (2) and (3) only


17. Consider the half equation: MnO4

−(aq) + xH2O(l) + ye− MnO2(s) + zOH−(aq) Which of the following combinations is correct? x y z A. 1 2 2 B. 2 2 4 C. 2 3 4 D. 4 3 8 18. Which of the following reagents can be used to distinguish between ammonium

sulphite solution and sodium sulphate solution?

(1) barium chloride solution (2) acidified potassium permanganate solution (3) sodium hydroxide solution

A. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) only

19. Which of the following statements concerning members of homologous series is

correct?

(1) They can be represented by same general formula. (2) There are gradual changes in physical properties among members. (3) Members of the same homologous series have same chemical

properties. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3)


20. Perspex is a polymer which has the following structure:

C C

H

H

CO2CH3

CH3

C C

H

H

CO2CH3

CH3

C C

H

H

CO2CH3

CH3

......

The percentage by mass of carbon in perspex is A. 30% B. 60% C. 75% D. 80% 21. The diagram below shows the apparatus used in the reduction of copper(II)

oxide with hydrogen.

Which of the following statements concerning the experiment is correct?

A. The black oxide changes to silvery grey solid. B. The product formed can no longer conduct electricity. C. The residual hydrogen is burnt as it is toxic. D. After reduction is complete, hydrogen is passed through the

apparatus until it is cold.


22. A brand of chocolate has 5 coloured beans A to E. A paper chromatogram was run for the 5 beans with water as solvent and it is shown below.

What is the total number of colourings used in this brand of chocolate? A. 4 B. 6 C. 8 D. 14 23. Sulphur dioxide can be prepared by (1) heating copper turning with concentrated sulphuric acid. (2) the action of dilute hydrochloric acid on sodium sulphite. (3) burning iron pyrite (FeS2) in air. A. (1) and (2)only. B. (1) and (3) only. C. (2) and (3) only. D. (1), (2) and (3).


24. A piece of filter paper moistened with sodium chloride solution is put between the two metals in each case.

Which of the following represents the order of tendency to form ions of the metals?

A. X > M > W > Z > Y B. W > Y > M > Z > X C. Y > X > Z > M > W D. X > Z > M > Y > W 25. Which of the following can reduce the emission of sulphur dioxide? (1) Installing catalytic converter in cars. (2) Using diesel with low sulphur content. (3) Increasing the height of the chimney. A. (1) only B. (2) only C. (2) and (3) only D. (1) and (3) only


26. A student used the propanoic acid obtained to carry out the following experiment:

Which of the following statements concerning the experiment is correct when the contents of the test tube were added to sodium carbonate solution?

(1) Two immiscible layers form. (2) Effervescence. (3) Pleasant smell is detected.

A. (1) and (2) only. B. (1) and (3) only. C. (2) and (3) only D. (1), (2) and (3) 27. The oxidation number of cobalt (Co) in [Co(NH3)6]3+ is

A. –3 B. +2 C. +3 D. +9


Directions: Each question below (Question Nos. 28 to 30) 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 opinion 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. The 1st statement is false but 2nd statement is true. D. Both statements are false.

1st statement

2nd statement

28. Magnesium chloride solution gives a white precipitate with lead(II) nitrate solution.

Magnesium has a higher position than lead in the metal activity series.

29. When hot saturated copper(II) sulphate solution is cooled, crystals will be formed.

Copper(II) sulphate is more soluble in hot water.

30. Concentrated sulphuric acid has a higher viscosity than hydrochloric acid.

Sulphuric acid has a larger intermolecular force than hydrochloric acid.


Section B 31. The bleaching actions of chlorine water and aqueous sulphur dioxide are

compared as shown below:

Sulphur dioxide Chlorine water (1) Bleaches by reduction . Bleaches by oxidation. (2) Bleaching action is slower

and milder. Bleaching action is faster and

more vigorous. (3) Bleaching effect is not

permanent and original colour will be restored later.

Bleaching effect can last for a longer period of time.

Which of the above combinations is correct? A. (1) and (2) only. B. (2) and (3) only. C. (1) and (3) only D. (1), (2) and (3) 32. Which of the following solutions, with the same volume and concentration, has

the lowest pH value?

A. Sodium chloride solution B. Ethanoic acid C. Hydrochloric acid D. Sulphuric acid

33. When an alkane of formula C12H26 is cracked, which of the following are the

possible products? (1) CH4 and C11H22 (2) C2H5 and C10H21 (3) C4H10 and C8H18 A. (1) only B. (2) only C. (1) and (3) only D. (1), (2) and (3)


34. Equal masses of excess zinc powder are separately treated with equal volume of 1 M hydrochloric acid and sulphuric acid. Which of the following is a correct description of what might occur?

Total volume of Initial rate hydrogen evolved of reaction A. smaller with hydrochloric acid faster with hydrochloric acid B. smaller with hydrochloric acid faster with sulphuric acid C. greater with hydrochloric acid faster with hydrochloric acid D. greater with hydrochloric acid faster with sulphuric acid 35. Which of the following polymers is/are made by condensation polymerization?



36. A student proposed a method to determine the concentration of citric acid in a sample of lemon juice by titration with standard sodium hydroxide solution. The method proposed consists of the following experimental procedures.

(1) Fill a burette, which has been well rinsed with deionised water

beforehand, with the standard sodium hydroxide solution. (2) Titrate the lemon juice in the flask with the sodium hydroxide

solution using methyl orange as the indicator. (3) Titration is repeated several times to obtain consistent results. Which of the above procedures are considered as inappropriate practices?

A. (1) and (2)only. B. (1) and (3) only. C. (2) and (3) only. D. (1), (2) and (3). 37. The nitric acid obtained by an industrial process contains 70% by mass of nitric

acid and has a density of 1.40 g cm−3. What is the volume of the acid required for dilution to 500 cm3 of 0.10 M nitric acid?

A. 0.32 cm3 B. 3.21 cm3 C. 2.25 cm3 D. 15.56 cm3 38. 80 cm3 of 5 M aqueous barium chloride reacts with 40 cm3 5 M aqueous

sodium sulphate. The mass of barium sulphate produced is A. 23.4 g B. 46.7 g C. 93.4 g D. 186.8 g


39. A student added 5 g of zinc to 50 cm3 of 1.00 M hydrochloric acid at 20 °C. Hydrogen was produced. The experiment was repeated at 30 °C and 40 °C. In each case the total volume of hydrogen produced was plotted against time. Which one of the graphs represents the volumes of hydrogen given off in the three experiments?


40. The equation below represents the reaction of nitrogen dioxide with water: 2NO2(g) + H2O(l) → HNO2(aq) + HNO3(aq) Which of the following statements concerning this reaction is/are correct? (1) Nitrogen dioxide acts as an oxidising agent. (2) Nitrogen dioxide acts as a reducing agent. (3) The oxidation number of oxygen in water changes from −2 to −1. A. (1) only. B. (2) only. C. (1) and (2) only. D. (2) and (3) only.

41. Consider the following detergents:

(1)

(2)

(3)

Which of the above detergents is/are biodegradable? A. (1) only B. (3) only C. (1) and (2) only D. (2) and (3) only


42. In the set-up shown below metal X is more reactive than metal Y.

Which of the following statements concerning this set-up is/are correct?

(1) Lemon juice acts as electrolyte. (2) The separation between the strips would affect the voltage. (3) Multimeter can be used instead of a voltmeter to measure the

voltage. A. (1) and (2) only. B. (2) and (3) only. C. (1) and (3) only D. (1), (2) and (3) 43. Which of the following statements concerning electrolyte is/are correct?

(1) Electrolyte conducts electricity and is decomposed in the process. (2) Electrolyte conducts electricity only when it dissolves in water. (3) Electrolyte conducts electricity as there are mobile electrons.



44.

A zinc-carbon cell is connected to a voltmeter as shown in the above diagram. Which of the following statements concerning the set-up is INCORRECT?

A. Electrons flow from the zinc case to the carbon rod in the external

circuit. B. The zinc case gradually becomes thinner as the cell discharges. C. Manganese(IV) oxide acts as an oxidizing agent. D. Ammonium chloride acts as a reducing agent.

45. Which of the following statements concerning urea methanal articles is/are

correct? (1) They deform upon heating. (2) They cannot be recycled by direct remoulding. (3) They are addition polymers. A. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) only


46. Consider the set-up shown below:

Which of the following statements are correct? (1) The solution around electrode X turns brown. (2) The mass of electrode Y increased. (3) Oxidation occurs at electrode X. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3)

47. Which of the following gases contains the largest number of atoms at room

temperature and pressure? (Molar volume of gas at room temperature and pressure = 24.0 dm3) A. 60 cm3 of ammonia. B. 40 cm3 of methane. C. 100 cm3 oxygen. D. 75 cm3 of carbon dioxide.

2006-ME-CHEM 2 -21-

Directions: Each question below (Question Nos. 48 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 opinion 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. The 1st statement is false but 2nd statement is true. D. Both statements are false.

1st statement

2nd statement

48. In the preparation of soapless

detergents, concentrated sulphuric acid and sodium hydroxide are required.

Concentrated sulphuric acid can react with sodium hydroxide to give a salt.

49. Galvanized iron has enhanced corrosion resistance.

Oxides of iron are formed when iron reacts with oxygen.

50. Sodium carbonate can be used to soften hard water which contains calcium ions.

Sodium carbonate reacts with calcium ions in hard water to form a precipitate.

END OF PAPER

d. rubidium has a higher reactivity with water than sodium.chemistryhk.com/chemmock/set 6-12/set 8...

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