There is no change in the colour of red litmus and blue litmus paper when introduced into an aqueous solution of sodium chloride. After passing direct current through the same solution, red litmus changes to blue colour. Which product is responsible for this change ? Mention any two uses of this product.

Explanation

`Sodium hydroxide // NaOli.`
(i) Degreasing netals
(ii) soaps and detergents
(iii) Paper nmaking
(iv) Artificial fibres.