Question

What happens when Copper reacts with moist air? ​

Answer 1

Copper metal when exposed to air turns green in colour due to corrosion. When copper vessel is exposed to air in rainy season, the metal reacts with gases and moisture and atmospheric gases to form a mixture of copper carbonate and copper hydroxide. This gives a green colour to the surface of copper metal.

Answer 2

Copper forms a green deposit on its surface when exposed to air which is usually a mixture of copper carbonate and copper hydroxide.

The chemical reaction is

2Cu + H2O + CO2 + O2 → Cu(OH)2 + CuCO3