Question

In one of the industrial processes used for the manufacture of sodium hydroxide, a gas X is formed as by product. The gas X reacts with lime water to give a compound Y which is used as a bleaching agent in chemical industry. Identify X and Y giving the chemical equation of the reactions involved.

Answer 1

Sodium hydroxide is manufactured by the electrolysis of a strong solution of sodium chloride (called brine). As a result, chlorine (X) is evolved at anode while hydrogen at cathode. Chlorine reacts with lime water containing slaked lime to form bleaching powder (Y)

`underset(("Lime  water"))("Ca"("OH")_2) + underset((X))("Cl"_2) -> underset("Bleaching Powder(Y)")("CaOCl"_2)+"H"_2"O"`