化學 1997 年 DSE、CE 選擇題（第 4 頁）

31.

Which of the following statements concerning citric acid is/are correct ?

(1)It is a strong acid.

(2)It is present in oranges.

(3)It exists as a solid at room temperature.

32.

Which of the following metal oxides can be reduced to the metal when heated with carbon ?

(1)aluminium oxide.

(2)lead(II) oxide.

(3)iron(III) oxide.

33.

Which of the following statements concerning the reaction of methane with bromine is/are correct ?

(1)It is an addition reaction.

(2)It is a substitution reaction.

(3)A similar reaction will occur if propane is used instead of methane.

34.

One mole of sulphur atoms has a mass twice that of one mole of oxygen atoms. Which of the following statements is/are correct ?

(1)2 g of sulphur and 1 g of oxygen each occupy the same volume at room temperature and pressure.

(2)2 g of sulphur and 1 g of oxygen each contain the same number of atoms.

(3)The number of atoms contained in one mole of sulphur is twice that contained in one mole of oxygen.

35.

Dilute ammonia solution is used in domestic glass cleansers because

(1)it can saponify grease.

(2)it is non-corrosive.

(3)it contains ammonium ions which can emulsify grease.

Which of the above statements is/are correct ?

36.

Which of the following substances can be used to distinguish between concentrated nitric acid and concentrated sulphuric acid ?

(1)sodium carbonate powder.

(2)copper turnings.

(3)cane sugar.

37.

Which of the following substances would react with sodium hydroxide solution ?

(1)ammonium chloride solution.

(2)copper(II) sulphate solution.

(3)ethanoic acid.

38.

Which of the following statements about using ethanol as a car fuel is correct ?

(1)Ethanol is a cleaner fuel than petrol.

(2)Using ethanol as a car fuel is economical in agricultural countries with sugar cane as the main crop.

(3)A car engine has to be suitably modified when using ethanol as a fuel.

39.

Concentrated sulphuric acid is corrosive to skin because

(1)it is a dehydrating agent.

(2)it is an oxidising agent.

(3)each molecule of sulphuric acid has two ionisable hydrogen atoms.

Which of the above statements are correct ?

40.

Which of the following methods can be used to solve the pollution problems associated with the disposal of plastic waste ?

(1)recycling of plastic.

(2)making biodegradable plastic.

(3)burning plastic waste in incinerators with tall chimneys.