Question

Sulphur dioxide and chlorine are both used as bleaching agents:

i. What is similar in the use of chlorine and sulphur dioxide as bleaching agents?

ii. How does the bleaching action of these two gases differ?

iii. What type of fibre should not be bleached using chlorine? Why should the use of chlorine be avoided for this fibre?​

Answer 1

Explanation:

Both sulphur dioxide and chlorine are good bleaching agents. Bleaching action of chlorine is based on oxidation while that of sulphur is based on reduction.

Chlorine acts with water to produce nascent oxygen. This oxygen combines with coloured substance and makes it colourless.

Sulphour dioxide removes oxygen from the coloured substance and makes it colourless. But atmospheric oxygen slowly takes place of the removed oxygen and because of which the material regains the colour