What quantity of electricity will liberate 0.125 mole of oxygen molecules during the electrolysis of dilute sodium chloride solution?

• A. 24,125 C
• B. 48,250 C
• C. 72,375 C
• D. 96,500 C

(a)(i) Give the names of two allotropes of sulphur.

(ii) State and explain what is observed when hydrogen sulphide is bubbled through acidified potassium tetraoxomanganatc (VII) solution

(iii) List one product of the reaction of sulphur (IV) oxide with hydrogen sulphide

(b)(i) What are the raw materials for the manufacture of tetraoxosulphate (VI) acid by the contact process?

(ii) Write an equation for the reaction that requires a catalyst in the contact process and state the catalyst used.

(iii) State the observation and the product formed when concentrated H\(_2\)SO\(_4\) reacts with each of the following:

I. Copper turnings Ii. A cube of sugar

(c)(i) Give three uses of sodium trioxocarbonate (IV).

(ii) What name is given to reactions of the following type?:

exposure to air

Na\(_2\)CO\(_3\) + 10H\(_2\)O\(_{(s)}\) \(\to\) Na\(_2\)CO\(_3\); H\(_2\)O\(_{(S)}\) + 9H\(_2\)O

(iii) Calculate the solubility of Na\(_2\)CO\(_3\) at 25°C, if 2.0 cm\(^3\) of its saturated solution at that temperature gave 1.75g of the anhydrous alt. [C = 12, O = 16, Na = 23].

Which of the following statements is NOT correct?

• A. The average kinetic energy of a gas is directly proportional to its temperature
• B. At constant tempearture, the volume of a gas increases as the pressure increases
• C. The pressure of a gas is inversely proportional to its volume
• D. The temperature of a gas is directly proportional to its volume

An atom 17 protons, 17 electrons and 18 neutrons has a mass number of

• A. 17
• B. 18
• C. 34
• D. 35

A hydrocarbon X which decolorizes bromine water but has no action on ammoniacal silver trioxonitrate (V) solution was found to have a molar mass of 58 g mol\(^{-1}\)

(a) Deduce the molecular formula of X. (H = 1, C = 12)

(b) Write the structures of two isomers of X.

Sulphur (IV) oxide travels a given distance in 10 sec. How long will it take equal volume of Helium to travel the same distance under the same conditions? [S = 32, O = 16, He = 4]

• A) 1.6sec
• B) 40sec
• C) 5.0sec
• D) 2.5sec

The periodic property that is used to determine whether a covalent molecule is polar or not is

• A. atomic radius
• B. ionization energy
• C. electron affinity
• D. electronegativity

Which of the following gases can be collected by the method of downward delivery?

• A. Chlorine
• B. Oxygen
• C. Ammonia
• D. Hydrogen

When ΔH is negative, a reaction is said to be

• A) endothermic
• B) exothermic
• C) reversible
• D) ionic

Which of the following methods can be used to remove temporary hardness from water?

• A. Boiling
• B. Filtration
• C. Distillation
• D. Chlorination