化學 1996 年 DSE、CE 選擇題（第 4 頁）

31.

For Questions 30 and 31, refer to the following experiment.

Which of the following statements concerning the above experiment is / are correct ?

(1)Platinum electrodes should be used.

(2)The concentration of Na⁺(aq) ions around the cathode increases.

(3)The solution changes from colourless to pink.

32.

Which of the following statements concerning one mole of nitrogen gas is / are correct ?

(Relative atomic masses : He = 4.0, N = 14.0; Avogadro constant = 6.02 × 10²³ mol⁻¹)

(1)It has a mass of 14.0 g.

(2)It occupies the same volume as 4.0 g of helium gas at room temperature and pressure.

(3)It contains 6.02 × 10²³ atoms of nitrogen.

33.

A mixture contains only copper(II) oxide and anhydrous copper(II) sulphate. Which of the following methods can be used to separate copper(II) oxide from the mixture ?

(1)Add water to the mixture and then filter.

(2)Add dilute nitric acid to the mixture and then filter.

(3)Add concentrated hydrochloric acid to the mixture and then filter.

34.

Which of the following statements concerning nylon and urea-methanal is / are correct ?

(1)They are formed by condensation polymerisation.

(2)They have cross-linkages between polymer chains.

(3)They are nitrogen-containing compounds.

35.

In which of the following processes will lead be produced ?

(1)the electrolysis of molten lead(II) bromide

(2)heating lead(II) oxide strongly

(3)adding magnesium to lead(II) nitrate solution

36.

Which of the following metals is / are present in solder ?

(1)copper

(2)lead

(3)iron

37.

In which of the following reactions does sulphur dioxide act as a reducing agent ?

(1)the production of sulphuric acid in the Contact Process

(2)the bleaching of a red petal

(3)the decolourisation of bromine water

38.

Which of the following substances are commonly found in the waste water produced by electroplating factories ?

(1)acids

(2)alkalis

(3)cyanides

39.

The atomic number of element X is 16. Which of the following statements concerning X are correct ?

(1)X can react with calcium to form an ionic compound.

(2)The oxide of X dissolves in water to form an acidic solution.

(3)X can conduct electricity in its molten state.

40.

Which of the following substances, if taken in excess, would affect the correct judgement of a car driver ?

(1)ethanol

(2)codeine

(3)morphine