Q12 of 30 Page 56

It has been noticed that silverware becomes black faster today than it did fifty years ago. What can be the reason for this?

Pollution of the environment has lead to an increase in sulphur present in the air. Now, since sulphur is readily available, silver reacts with it and thus becomes black:

2Ag + H2S (present in air) → Ag2S + H2


The black coating is of Ag2S. Fifty years ago, the air was less polluted so was the amount of sulphur in the air and thus less sulphur was available for reacting with silver jewellery.


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