(a) What is the structure of:

(i) graphite:
(ii) diamond
 (ii) Explain briefly why diamond is hard and a non-conductor of electricity while graphite is soft and an electrical conductor,

(b)i. State what is achieved at each of the following stages in the purification of town water supply:

- aeration;
- screening
- sedimentation.

(ii) Name two substances responsible for hardness in water.

(iii) State two methods for the removal of hardness in water.

(iv) Give one disadvantage of hard water

(c)i). Describe briefly the extraction of tin from its ore.

(ii) Write a balanced chemical equation for the reaction.

(iii) Write an equation for the reaction of tin with:
- oxygen;
- chlorine.

(a)i. With the aid of an equation, explain briefly why aluminum metal is not affected by air.

(ii) In the extraction of aluminum from bauxite, state the:
- substance used for purifying the ore;
- composition of the mixture electrolyzed.

(b) ZnO is an amphoteric oxide. Write equations to illustrate this statement.

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

(ii) Explain briefly why a solution of trioxonitrate(V) acid turns yellowish on storage for some time.

(ii) Describe briefly how trioxonitrate(V) ions could be tested for in the laboratory.

(d) Write balanced chemical equations for the preparation of hydrogen chloride.

(i) using concentrated H\(_{2}\)SO\(_{4}\):

(ii) by direct combination of its constituent elements.

(iii) State one use of hydrogen chloride. 

(a)(i) Define the first ionization energy of an element

(ii) Consider the following table and use it to answer te question that follows

Explain briefly why the first ionization energy of B is less than that of Be despite the fact that the atomic number of B is greater than that of Be.

(b) When Titanium chloride was electrolysed by passing 0.12 A current through the solution for 500 seconds, 0.015 g of titanium was deposited. What is the charge on the titanium ion?
[ IF= 96500 C, Ti= 48.0 ]

(c)(i) Aluminium can be obtained by the application of electrolysis. State the electrolyte which yields aluminium on electrolysis.

(ii) Name two major factors which would favour the siting of an aluminium smelter in a country.

(d)(i) Define the term paramagnetism.

(ii) Consider the following ions: 24\(^{Cr ^{2+}}\), 24\(^{Cr^{6+}}\)

(I) Deduce the number of unpaired electrons in each of the ions. 

(II) State which of the ions will have a greater power of paramagnetism

(l) Give a reason for the answer stated in (d)(ii)(II)

(a) (i) Define the term Avogadro's number.

(ii) If 2.30 g of an oxide of nitrogen, x, contains 3.01 x 10\(^{22}\) molecules, calculate the molar mass of x.

(iii) Deduce the formula of x. N, =6.02 x 10", N =14.0, O = 16.0]

(b)(i) Describe briefly what happens when each of the following substances are added to water:

(I) CCI\(_{4}\);     (II) SiCI\(_{4}\), 

(ii) Explain briefly why the reactions in (a)(i), (b)(i), (I) and (b)(ii) (II) are different Study the diagram below and answer the questions that follow.

(c) Study the diagram below and answer the questions that follow.

(i) What is the set up used for?

(a)i.  Define an acid according to the Lewis concept

ii. Give one example of a Lewis acid

(b) Explain salting out in soap preparation

(c) State the reagent and condition necessary for the following conversion
H−C≡C−H→Ag−C≡C−Ag

(d) What is the percentage abundance of an isotope?

(e)i. Why does the element with atomic number 18 not have an oxide?

ii. Explain why chlorine(I) oxide has a low melting point

(f). Describe a test to distinguish between concentrated HNO3 and concentrated H2SO4

(g) State two differences between an electrochemical cell and an electrolytic cell

(h) How does the trend in ionization energy affect the reactivity of group 1 elements?

(i).Define the term molecular formula

(j) State which of the gases H2 and NH3 would deviate more from ideal behaviour. Give reasons for the answer stated above