State the atoms represented as shown below:

(a) State the relationship between the two atoms.

(b) What is the difference between them?

(c) Give two examples of elements which exhibit the phenomenon illustrated above.

(a)State three characteristics of a catalyst.

(b) Mention one manufacturing process in which each of the following metals is used as a catalyst:

(i) iron;

(ii) nickel;

(iii) platinum

(c) Give one example of an organic catalyst.

A colourless and odourless gas X burns in oxygen with a pale blue flame.

(a) Suggest two gases which X could be.

(b) Give one chemical test that could be used to confirm which of the two gases X is.

 Methane is obtained when a powdered mixture of anhydrous sodium ethanoate and soda-lime is heated in a hard glass test tube.

(a) Write an equation for the reaction.

b) Explain briefly why soda-lime is preferred to sodium hydroxide for the preparation.

(a) Give the products of electrolysis of dilute copper (II) tetraoxosulphate(VI) solution using the following materials as electrodes:

(i) carbon rod;

(ii) copper rods

(b) For each of the process in (a) above;

(i) write the anodic half reaction;

(ii) state how electrolysis affects the pH of electrolyte