Question

explain the following-

a) corrosion of copper b.) corrosion of aluminium and corrosion of silver

Answer 1

a) Corrosion of copper – when copper metal is exposed to moist air, a green layer is developed on it due to formation of basic copper carbonate..The reaction is as follows:

2Cu + O₂ + CO₂ + H₂O → CuCO₃.Cu(OH)₂

Green layer

b) Corrosion of aluminium- Aluminium react with oxygen present in air to form a dull layer of aluminium oxide on the surface of the aluminum vessel due to which vessels acquire a dull appearance.

c) Corrosion of silver- Silver reacts with hydrogen sulphide present in the air to form a layer of silver sulphide which is black in colour on the surface of the silver article due to which it appears black.