Sodium hydroxide is made by the electrolysis of brine.

a. Draw and label a simplified diagram of the cell used in this process. Make certain that you have labelled on the diagram:

(i) The electrolyte

(ii) The material of the electrodes

(iii) The material of the membrane.

b. Write equations for the reactions which take place at the cathode and anode. State clearly whether a reaction is oxidation or reduction. 

c. Give two large-scale uses of the products of this electrolytic process.

d. Comment on the following statement: ‘This electrolytic process is a very expensive one’.

e. Both the membrane cell and the older mercury cell make sodium hydroxide of high purity. Explain why the membrane cell is now the preferred way of making sodium hydroxide.