(a) Give one reason why a collision between reactants may not produce new species.

(b) Explain, illustrating with appropriate equation(s), why an aqueous solution of aluminium chloride is acidic.

(a) Give the formula indicating the relationship between entropy, free energy and enthalpy changes of a system.

(b) For each of the following, state whether entropy change is positive, negative or zero.

(i) H\(_2\)O\(_{(g)}\) -> H\(_2\)O\(_{(g)}\)

(ii) Cl\(_{2(g)}\) ---> 2CI\(_{(g)}\)

(iii) HCI\(_{(g)}\) -> HCl\(_{(g)}\)

Benzene contains six carbon atoms and six hydrogen atoms.

(a)(i) Draw two stable structures of benzene to show how these atoms are arranged.

(ii) What is the concept behind these structures?

(b) Give (i) two uses of benzene. (ii) one industrial source of benzene.

(a) Arrange the first three members of the halogen family in their increasing order of electronegativity. Give the reason for your answer.

(b) State and explain what happens when chlorine reacts with starch iodide paper.

(a) Name the type of solid structure possessed by:

(i) diamond;

(ii) iodine;

(iii) sodium chloride.

(b) Give:

(i) one alloy of tin:

(ii) a common reducing agent which is a compound of tin.