Question

The hair dye available in the market contains two bottles, one containing dye and other containing hydrogen peroxide. The bottles are mixed before applying the dye. The function of hydrogen peroxide is

(a) to dilute the dye.

(b) to oxidise the dye to give desired colour.

(c) to reduce the dye to give desired colour.

(d) to acidify the dye solution.

Answer 1

(b) to oxidise the dye to give desired colour.

In dye mixtures, hydrogen peroxide acts as an oxidizing agent. It oxidizes melanins, organic compounds which absorb visible light and give hair its colour; this oxidation removes the parts of the compounds that cause colour, and causes the natural pale yellow of keratin (the protein that makes up hair) to show through.