(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.

Liquefied air is mainly a mixture of nitrogen and oxygen which can be separated into its components by fractional distillation (Boiling point of nitrogen is 196°C, Boiling point of oxygen is 174°C)

(a) Name the fraction which distills over first. Give the reason for your answer.

(b) Give another industrial application of fractional distillation as a separation technique.