Question

Explain why bleaching action of cl2 is permanent while that of so2 is temporary ?

Answer 1

Sulphur dioxide is a temporary bleaching agent, unlike Chlorine, which is a permanent bleaching agent! This is because the mechanism for bleaching is different:

SO2-Reduction => TEMPORARY

Cl2-Oxidation => PERMANENT

Sulphur 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.

Answer 2

Answer:

Sulphur dioxide is a temporary bleaching agent, unlike Chlorine, which is a permanent bleaching agent! This is because the mechanism for bleaching is different: SO2-Reduction => TEMPORARY. Cl2-Oxidation => PERMANENT.