If copper is kept open in air, it slowly loses its shining brown surface

• GC Metals Non-Metals

If copper is kept open in air, it slowly loses its shining brown surface and gains a green coating. It is due to the formation of

1. CuSO₄
2. CuCO₃
3. Cu(NO₃)₂
4. CuO

Answer

Copper reacts with moist carbon dioxide in the air and form green colour basic copper carbonate.

The correct option is B.