Question

a student has collecting the Silver coins and the copper coins one day he observed a black coating on Silver coins and green coating on copper coins give the chemical name of black and green coating how are they formed

Answer 1

Hey mate here is your answer:-

*since the silver coin is coated with a black coating which is a layer of silver sulphide on it which gives black colour to the silver .

"Ag+S2----Ag2S(black coated)"

*Since the copper coin is coated with green coating, which is a layer of copper basic carbonate. In the presence of the moisture, the copper is coated with a greenish layer known as copper basic carbonate.

"Cu+CO2+H2O+O2---CuCO3.Cu(OH)2{green coated}".

Hope it helps bro