化學 1992 年 DSE、CE 選擇題

1.

Rubidium (Rb) is a group I element below potassium in the Periodic Table. Which of the following statements about rubidium is correct ?

2.

X and Y are elements. The melting points of their chlorides are given below:

	Melting point (°C)
Chloride of X	772
Chloride of Y	−68

Which of the following statements is correct ?

3.

Which of the following electron diagrams is correct ?

4.

Consider the following table:

Element	W	X	Y	Z
Atomic number	9	10	14	19

Which of the following elements is likely to be an oxidizing agent ?

5.

0.01 mol of C₂H₅OH is burnt completely in oxygen. What are the numbers of moles of carbon dioxide and water formed respectively ?

	carbon dioxide	water
	0.01	0.03
	0.02	0.03
	0.02	0.06
	0.04	0.06

6.

Which of the following gases, each having a mass of 10.0 g, has the greatest number of molecules at room temperature and pressure ? (Relative atomic masses: C = 12.0; N = 14.0; O = 16.0; F = 19.0; Ne = 20.2)

7.

The manufacture of sulphuric acid can be represented by the following flow diagram: S —(Stage I)→ SO₂ —(Stage II)→ SO₃ —(Stage III)→ H₂S₂O₇ —(Stage IV)→ H₂SO₄ Which stage involves the greatest change in the oxidation number of sulphur ?

8.

Directions: Q.9 and Q.10 refer to the following diagrams:

Which of the following represents the correct order of activity of the metals P, Q, R and S ?

9.

Directions: Q.9 and Q.10 refer to the following diagrams:

Which of the two metals used as electrodes would give the largest cell voltage ?

10.

Consider the following diagram:

Which of the following combinations is correct?

	Reactant X	Reactant Y
	H₂(g)	dilute H₂SO₄
	CO(g)	dilute HNO₃
	NH₃(g)	dilute HCl
	C(s)	concentrated HCl