(a)(i) Outline the steps involved in the purification of water for town supply.

(ii) Give two cations that can cause hardness in water.

(iii) State two disadvantages of hardness of water.

(iv) List two sources of water pollution.

(b)(i) Explain briefly why water is a good solvent for sodium chloride but not for oil.

(ii) State the function of H\(_2\)SO\(_4\) in each of the following reaction equations:

(i) C\(_2\)H\(_5\)OH\(_{(l)}\) \(\to\)  C\(_2\)H\(_{4(g)}\)

(ii) MgO\(_{(s)}\) + H\(_2\)SO\(_4\)\(_{(aq)}\) —> MgSO\(_{4(aq)}\) + H\(_2\)O\(_{(l)}\)

(iii) C\(_{(s)}\) + conc. H\(_2\)SO\(_4\) --> CO\(_{(g)}\) + SO\(_{2(g)}\) + H\(_2\)O\(_{(l)}\)

(c) (i) Give the two products formed when chlorine water is exposed to sunlight.

(ii) I. Which of the compounds is suitable for the preparation of standard alkaline solution?

II. Give a reason for your answer in (c)(ii)I

(a)(i) Explain briefly each of the following terms: I. anode; II. cathode.

(ii) Sodium and aluminium are extracted by the electrolysis of molten sodium chloride and alumina respectively. Write balanced equations for the reactions at the anode and cathode during the extraction of: I. sodium; II. aluminium.

(iii) Explain briefly why extraction of aluminium is considered environmentally friendly while that of sodium is not.

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

K\(_2\)Cr\(_2\)O\(_7\) + HC1--> KCI + CrCl\(_3\) + H\(_2\)O + Cl\(_2\)

(i) Explain briefly why this reaction is redox.

(ii) Write balanced half equations for the reaction.

(iii) Write the over-all balanced reaction equation.

(c) During the electrolysis of molten Al\(_2\)O\(_3\), a current of 6A was passed through the electrolyte for 1 hr. 30 mins. Calculate the mass of aluminium deposited at the cathode.

(a)(i) Define the term functional group.

(ii) Name the functional groups present in the following compound:

(b) Consider the following structure of an organic compound, Q.

(1) Name compound Q.

(ii) Write the balanced equation for the complete combustion of compound Q.

(iii) What type of reaction will compound Q undergo with chlorine?

(vi) Draw the structure of-the alkene that is an isomer of compound Q.

(c) A chemistry student was provided with four samples of organic compounds, A, B, C, and D. Samples A and B each decolourized bromine in tetrachloromethane but only sample B reacted with a solution of ammoniacal silver trioxonitrate (V) to give a white precipitate. Sample D reacted with sodium trioxocarbonate (IV) to liberate carbon (IV) oxide. When heat was applied to the mixture of samples C and D in a test tube and drops of concentrated tetraoxosulphate (VI) acid added, a product with a fruity odour was formed.

(i) Name the family of organic compounds to which samples A, B, C, and D belong.

(ii) State why samples A and B reacted with bromine in tetrachloromethane.

(iii) State the reason why sample B gave a white precipitate with the solution of ammoniacal silver trioxocarbonate (V).

(iv) Give the name o f the reactions between' samples C and D.

(v) State the two roles of the concentrated tetraoxosulphate (VI) acid in the reaction in (a)(iv).

(d) (i) Describe briefly the production of biogas using a biogas generator.

(ii) State two uses of biogas.

(a)(i) What is the common name given to the group VII elements?

(ii) Name the hydrides of the first two elements in group VII.

(iii) State three chemical properties of group VII elements.

(b) Copy and complete the following table:

(c)(i) Define each of the followinc processes: I. nuclear fission; II. nuclear fusion.

(ii) Give one use of each process in (c)(i).

(d)(i) List three types of radiation that are produced during radioactivity.

(ii) Arrange the radiations listed in

(d)(i) in order of increasing: I. penetrating power; II. ionizing power.

(a)(i) Define each of the following terms: I. normal salt. II. acid salt.

(ii) Tetraoxosulphate (VI) acid and sodium hydroxide react to produce salt and water. Write a balanced chemical equation fir the formation of: I. a normal salt; II. an acid salt.

(b)(i) Explain briefly the term acid-base indicator.

(ii) Copy and complete the following table.

(iii) For each of the following titrations, state the most suitable indicator: I. strong acid against strong base; II. strong acid against weak base; iii. weak acid against strong base.

(c) Baking soda and hydrochloric acid react according to the following equation:

NaHCO\(_{3(aq)}\) + HCI\(_{(aq)}\) ---> NaCl\(_{(aq)}\) CO\(_{2(g)}\) + H\(_2\)O\(_{(l)}\). Calculate the mass of baking soda that would produce 10g of ccrbon (IV) oxide. [H = 1.00, C = 12.0, 0 = 16.0, Na = 23.0]

(d) Give a reason why a given mass of sodium hydroxide pellets cannot be used to prepare a standard solution.

NaHCO\(_3\) + HCI --> NaCI + CO\(_2\) + H\(_2\)O

84g NaHCO\(_3\)  --> 44g CO\(_2\)

Xg --> 10g CO\(_2\)
Xg = \(\frac{84 \times 10}{44}\)

= 19.09g

= 19.1g.

(d) give a reason why a given mass of sodium hydroxide pellets cannot be used to prepare a standard solution: Sodium hydroxide absorbs water/deliquescent and absorbs carbon IV oxide from air/and this would make mass taken unreliable/add to its mass.