Question

When the powder of a common metal is heated in an open china dish ,

its colour turns black. However when hydrogen is passed over the hot

black substance so formed, it regains its original colour.

(a). What type of chemical reaction takes place in each of the two given

steps?

(b). Name the metal initially taken. Write balanced chemical equations

for both reactions.​

Answer 1

Explanation:

open air, its is oxidised to form copper (II) oxide which is black in colour. The reaction is known as oxidation reaction. On passing hydrogen gas over the hot substance, the original colour of the metal is regained. It is an example of reduction reaction.