化學 2009 年 DSE、CE 選擇題（第 3 頁）

21.

Which of the following methods are used to treat solid wastes in Hong Kong ?

(1)recycling of metal wastes

(2)using plastic wastes as fuel

(3)burying domestic solid wastes in landfill sites

22.

A substance has a high melting point and does not conduct electricity when in solid state. It may be

(1)a compound with giant molecules.

(2)an element with giant covalent structure.

(3)a compound with giant ionic structure.

23.

Which of the following substances can be used to distinguish between magnesium nitrate solution and silver nitrate solution ?

(1)zinc strip

(2)ammonium nitrate solution

(3)potassium chloride solution

24.

Which of the following substances can react with acidified potassium permanganate solution ?

(1)propene

(2)potassium iodide solution

(3)sodium sulphite solution

25.

Which of the following hazard warning labels should be displayed on the reagent bottle of methanol ?

26.

Which of the following measures can help reduce the level of carbon monoxide at the road side ?

(1)using liquefied petroleum gas as fuel for motor vehicles

(2)installing catalytic converter for motor vehicles

(3)installing electrostatic precipitator for motor vehicles

27.

Esters can be used to make

(1)perfumes.

(2)food additives.

(3)solvent for paints.

28.

For Questions 28–30, decide whether each of the two statements is true or false. If both are true, decide whether the second correctly explains the first.

A.Both are true and the second correctly explains the first.

B.Both are true but the second does not correctly explain the first.

C.The first is false but the second is true.

D.Both are false.

1st statement	2nd statement
Ammonium chloride is an ionic compound.	Ammonium chloride can conduct electricity in aqueous state.

29.

For Questions 28–30, decide whether each of the two statements is true or false. If both are true, decide whether the second correctly explains the first.

A.Both are true and the second correctly explains the first.

B.Both are true but the second does not correctly explain the first.

C.The first is false but the second is true.

D.Both are false.

1st statement	2nd statement
Copper(II) carbonate dissolves in water to give a blue solution.	All solid compounds with copper(II) as the only cations are blue in colour.

30.

For Questions 28–30, decide whether each of the two statements is true or false. If both are true, decide whether the second correctly explains the first.

A.Both are true and the second correctly explains the first.

B.Both are true but the second does not correctly explain the first.

C.The first is false but the second is true.

D.Both are false.

1st statement	2nd statement
When sulphur dioxide is added to sodium bromide solution, the mixture obtained is colourless.	Sulphur dioxide can act as a bleaching agent.