(a) What happens when a concentrated solution of sodium chloride (brine) is electrolysed? Write the equation of the reaction involved.
(b) Why is the electrolysis of a concentrated solution of sodium chloride known as Chlor-alkali process?
(c) Name three products of the chlor-alkali process. State two uses of each of these products.
(a) When a concentrated solution of sodium chloride is electrolysed, it decomposes to form sodium hydroxide, chlorine and hydrogen.
2NaCl(aq) + 2H2O(l) + Electricity + (Electrolysis) → 2NaCH(aq) + Cl2(g) + H2(g)
(b) Because of the products formed: Chlor for chlorine and alkali for sodium hydroxide.
(c) Sodium hydroxide, chlorine and hydrogen.
Uses of Sodium hydroxide:
(i) It is used for making soaps and detergents.
(ii) It is used in the manufacture of paper.
Uses of chlorine:
(i) It is used in the production of bleaching powder.
(ii) It is used in the production of hydrochloric acid.
Uses of hydrogen:
(i) It is used in the production of hydrochloric acid.
(ii) It is used in the hydrogenation of oils.