Consider the reaction represented by the equation: 2H2SO 4(aq0 + C(s) → 2H2O(l) + 2SO2(g) + CO 2(g) H2SO 4 is acting as

• A. a catalyst
• B. an oxidizing agent
• C. a reducing agent
• D. a sulphonating agent

(a)(i) Outline a suitable procedure for the preparation of ZnCl\(_2\) crystals stating from zinc granules.

(ii) Write a balanced equation for the reaction in (a)(i).

(b) Considei' the following solutions: Na\(_2\)SO\(_{4(aq)}\), CH3COOK\(_{(aq)}\), Pb(NO\(_3\))\(_{2(aq)}\) and MgCl\(_2\). Which of them has/have a pH

(i) greater than 7;

(ii) equal to 7;

(iii) less than 7?

(c)(i) Determine the oxidation number of Mn in I. MnO\(_2\); II. KMnO\(_4\).

(ii) State one laboratory use of each of the .compounds in (c)(i).

(d) Explain why oxidation and reduction processes are complementary.

(e) Consider the reaction represented by the equation: Fe\(_{(s)}\) + 2Ag\(^+_{(aq)}\) \(\to\) Fe\(^{2+}_{(aq)}\) + 2Ag\(_{(s)}\)

(i) Write a balanced ionic half equations for the reaction.

(ii) Which of the species is I. oxidized; II. reduced?

(iii) State the change in the oxidation number of silver during the reaction.

The separation of petroleum fractions depends on the differences in their

• A. boiling points
• B. molar masses
• C. melting point
• D. solubilities

Which of the following alloys does not contain copper? l. Brass II. Bronze III. Steel

• A. l only
• B. ll only
• C. lll only
• D. ll and lll only

Which of the following elements has the electronic configuration: 1s²2s²2p⁶3s²3p¹

• A. Al
• B. Na
• C. N
• D. S

Which of the following raw materials is used in the plastic industry ?

• A. Calcium
• B. Ethene
• C. Hydrogen
• D. Methane

How many protons does²⁰₄₀Ca contain?

• A. 20
• A. 20
• C. 40
• D. 60

Ethanol reacts with excess acidified K2Cr 2O7 to produce

• A. ethanal
• B. ethane
• C. ethanoic acid
• D. ethylethanoate

Which of the following salts is insoluble in water?

• A. Pb(NO₃)₂
• B. Na₂CO₃
• C. AgNO₃
• D. AgCI.

(a) (i) State Boyle's law.

(ii) Give the mathematical expression of Boyle's law.

(iii) Sketch the graphical representation of Boyle's law.

(b) A given mass of gas occupied 500 cm3 at 30°C and 6.5 x 104 Nm\(^{-2}\). Calculate the volume of the gas at s.t.p. [ Standard pressure = 1.01 x 105 Nm\(^{-2}\)]

(c) Explain why an inflated balloon expands in warm water.

(d)(i) What is meant by the term vapour density? (ii) Determine the vapour density of SO\(_{2}\). [ S = 32, O = 16 ]

(e)(i) Which of the following gases, SO\(_{2}\) and NH\(_{3}\) can be collected by I. upward delivery; II. downward delivery?

(ii) What would be the nature of the solution formed by dissolving each of the following substances in water separately. I. SO\(_{2}\) II. NH\(_{3}\)

(iii) State the property exhibited by SO\(_{2}\) and NH\(_{3}\) in the following equations:

I. 2H\(_{2}\)S\(_{(aq)}\) + SO\(_{2(g)}\) \(\to\) 3S\(_{(s)}\) + 2H\(_{2}\)O\(_{(/)}\)

II. 3CuO\(_{(s)}\) + 2NH\(_{3(g)}\) \(\to\) 3Cu\(_{(s)}\) + 3H\(_{2}\)O\(_{(/)}\) + N\(_{2(s)}\).

(f) State two alloys of tin.

(ii) Give one use of each of the alloys in (f)(i).