Question

Give reasons for the following: a) Silver and copper lose their shine when they are exposed to air. Name the substance formed on their surface in each case. b) Tarnished copper vessels are cleaned with tamarind juice. c) Aluminium is more reactive than iron yet there is less corrosion of aluminium as compared to iron when both are exposed to air.

Answer 1

The substance which forms on silver is silver sulphide.And other which forms on Cu is copper carbonate(CuCO3).Silver sulphide and Copper carbonate are base which when reacts with acid(Tamarind is acidic) then it nuetralise and thus cleaned.
The third questions answer is that it is aluminium because it forms a protective layer of aluminium oxide.But Fe can't.
Hope this will help you.