A student has been collecting silver coins and copper coins. One day she observed a black coating on silver coins and a green coating on copper coins. Which chemical phenomenon is responsible for these coatings? Write the names of black and green coatings.
A). When silver reacts with hydrogen sulphide in presence of air (oxygen)
to form a silver sulphide in black colour
The equation is:-
B). The Copper forms a green deposit on its surface when exposed to moist air. This is usually basic copper (II) sulphate.