Question
Fri March 04, 2011 By: Aditya Bansal

Why is the bleaching by chlorine permanent while that of SO2 temporary?

Expert Reply
Fri March 04, 2011

Dear Student

The bleaching action by chlorine is based on Oxidation means it requires nascent oxygen for
Bleaching action. While sulphur dioxide bleaching is based upon the reduction (Use of the 
nascent hydrogen)
Another difference is the bleaching action of sulphur dioxide is temporary while bleaching 
Action of chlorine is permanent. 
Basically bleaching action by chlorine is strong-Used for bleaching cotton, jute,It also
Damages delicate fibres by vigorous reaction. 
While SO2 is Mild bleaching agent..Used to bleach delicate fibres like silk,wool..Does not 
damage fabric as its not strong.

We hope that clarifies your query.

Regards

Team

Topperlearning

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