Question

A reddish brown metal A when exposed to moist air forms a green layer B. When A is heated at different temperatures in the presence of O₂ , it forms two types of oxides - C (black) and D (red). Identify A, B, C, D and write the balanced equation.

Answer 1

"Copper metal when presented to air turns green in colour because of consumption.

At the point when the copper vessel is presented to air in blustery season, the metal responds with gases and dampness and barometrical gases to form a blend of copper carbonate and copper hydroxide. This gives green colour to the surface of the copper metal.

The reaction is as follows:

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

2Cu + O2 → 2CuO

CuO + H2 → Cu + H2O

A: Cu

B: Cu(OH)2

C: 2CuO

D: Cu

"