1 g of copper powder was taken in a China dish and heated. What change takes place on heating ? When hydrogen gas is passed over this heated substance, a visible change is seen in it. Give the chemical equations of reactions, the name and the colour of the products formed in each case.

1 g of copper powder was taken in a China dish and heated. What change

1.	1 g of copper powder was taken in a China dish and heated. What change takes place on heating ? When hydrogen gas is passed over this heated substance, a visible change is seen in it. Give the chemical equations of reactions, the name and the colour of the products formed in each case.
Answer» Solution :The SURFACE of copper powder becomes black. This is due to formation of copper oxide. `2CU + O_2 overset(Heat)rarrunderset((black))underset("Copper oxide")(2CuO)` When hydrogen is passed over copper oxide, the black SUBSTANCE turns BROWN due to the formation of copper. `CUO + H_2 rarrunderset(("Copper Brown"))(Cu) + H_2O`