a)(i) Give two uses of ammonia.

(ii) Name the process by which ammoniacal liquor can be obtained from coal and list two other products of the reaction

(iii) What type of reaction is involved in the conversion of ammoniacal liquor to (NH\(_4\))\(_2\)SO\(_4\) by dilute H\(_2\)SO\(_4\)?

(iv) Sketch and label an energy profile diagram to show the effect of presence of Pt/Rh on the reaction represented by the following equation: 4NH\(_3\) + 5O\(_2\)  \(\to\) 6H\(_2\)O + 4NO; \(\Delta\)H = —907 kJmol\(^1\)

(b) Rock salt is an impure form of sodium chloride.

(i) Outline a suitable procedure for preparing a pure sample of sodium chloride from rock salt.

(ii) State two methods that can be used to prepare chlorine from rock salt. Write an appropriate equation in each case.

(c) Lead pigments were used in a water colour painting which turned black after prolonged exposure to an air pollutant. The original colour was restored by using H\(_2\)O\(_2\) which converted the black substance to a simple, white lead (II) salt.

(i) Which pollutant turned the painting black?

(ii) Write the formula of the black substance

(iii) What is the white salt?

(iv) State the role of H\(_2\)O in the restoration process.

(a) State three characteristic properties of

(i) electrovalent compounds;

(ii) alpha particles

(iii) catalysts

(b)(i) Write the electronic configuration of silicon (atomic number 14) and state the group to which it belongs in the Periodic Table.

(ii) State the type of chemical bonding between silicon and oxygen in SiO\(_2\)

(iii) A chip used in a microcomputer contains 5.72 x 10\(^{-3}\)g of silicon, calculate the number of silicon atoms in the chip.

[Si = 28; Avogadro constant = 6.02 x 10\(^{23}\) mol\(^{-1}\)]

(c) An element X belongs to the same group as sodium but is more reactive.

(i) Suggest with reason whether X would be a reducing or oxidizing agent.

(ii) What would be a suitable method of storing X in the laboratory?

(iii) Describe briefly what would be observed if a small piece of X were dropped into a trough of cold water which had been coloured with red litmus.

(iv) Write an equation to show how the oxide of X would react with dilute HCI.

(v) Suggest the likely colour of the salts of X

(a)(i) Explain what is meant by acid anhydride and give one example

(ii) State three chemical properties of hydrochloric acid.

(b) Explain each of the following observations:

(i) Tetraoxosulphate (VI) acid can form two types of salts unlike trioxonitrate (V) acid.

(ii) Copper and iron react with concentrated H\(_2\)SO\(_4\) but only one of them reacts with the dilute acid.

(iii) On adding dilute H\(_2\)SO\(_4\) separately to zinc dust and zinc granules of the same mass, the dust produced more vigorous effervescence.

(c)(i) Define activation energy.

(ii) Sketch and label an energy profile diagram for the following reaction: A + B --> C + D; AH = xkJmol\(^{-1}\)

(iii) Explain why the heat of reaction of the mineral acids with sodium hydroxide is constant in value.

(d) Consider the reaction represented by the following equation:

Q\(_{(s)}\) \(\rightleftharpoons\) Q\(_{(l)}\) \(\Delta\)  = xkJmol\(^{-1}\)

(i) State with reason which of Q\(_{(s)}\) and O\(_{(J)}\) has the higher entropy.

(ii) What will be the effect of decrease in temperature on the system at equilibrium?

(a)(i) Draw and label a simple cell for the electrolytic purification of copper.

(ii) Write can equation for the reaction at each electrode in (a)(i) above.

(iii) State with reason whether the Daniell cell is an electrolytic cell or an electrochemical cell.

(iv) What is the function of MnO\(_2\) in the Laclanche cell?

(b) Consider the following equation: MnO\(^-_4\) + 8H\(^+\) + xe\(^-\) \(\to\) Mn\(^{2+}\) + yH\(_2\)O. State the

(i) values of x and y;

(ii) oxidation state of Mn in MnO\(^-_4\).

(c)(i) List three factors that affect selective discharge of ions during electrolysis

(ii) State Faraday's second law of electrolysis.

(iii) A voltameter containing silver trioxonitrate(V) solution was connected in series to another voltameter containing copper (II) tetraoxosulphate(VI) solution. When a current ri 0.200 ampere was passed through the solutions, 0.780g of silver was deposited. Calculate the

I. mass of copper that would be deposited in the copper voltameter

II. quantity of electricity used and the time of current flow. [Cu = 63.5 ; Ag = 108; 1F = 96500C]

(a)(i) State three characteristics of a homologous series.

(ii) Give the name and structural formula of the second member of the alkyne series.

(iii) Write an equation to represent the combustion of ethane in excess oxygen.

(b) Name the type of reaction involved in the conversion of ethanol to

(i) ethene;

(ii) ethylethanoate;

(iii) chloroethane;

(iv) ethoxide

(v) ethanoic acid

(c) Consider the following compound.

(i) Write its IUPAC name.

(ii) Give its molecular formula and empirical formula

(iii) List the products of its H H 0 reaction with saturated Na\(_2\)CO\(_3\) solution.

(iv) State with reason whether its boiling point will be higher or lower than that of the corresponding alkane.

(d) A vegetable oil X was treated with activated charcoal and then with a gas Y in the presence of a catalyst in order to manufacture

(i) Identify Y.

(ii) State the function of the activated charcoal.

(iii) What is the catalyst used?

(iv) If a sample of X is heated with concentrated sodium hydroxide solution, list the products that will be obtained.