Chemicals from Common Salt - Preparation and Uses of Bleaching Powder

BLEACHING POWDER:-

You have already come to know that chlorine is produced during the electrolysis of aqueous sodium chloride (brine). This chlorine gas is used for the manufacture of bleaching powder. Bleaching powder is produced by the action of chlorine on dry slaked lime [Ca(OH)₂]. Bleaching powder is represented as CaOCl2, though the actual composition is quite complex.

Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂O

Bleaching powder is used –

(i) for bleaching cotton and linen in the textile industry, for bleaching wood pulp in paper factories and for bleaching washed clothes in laundry

(ii) as an oxidising agent in many chemical industries

(iii) to make drinking water free from germs.