Question

When hydrogen gas is passed over the black solid, it turns brown and
forms copper again. Why does this happen?


(a) reverse reaction takes place and hydrogen is being reduced


(b) reverse reaction takes place and the black solid is being oxidised


(c) reverse reaction takes place and the black solid is being reduced


(d) reverse reaction takes place and copper is being reduced​

Answer 1

The reaction is as follows.It is a combination reaction. If hydrogen gas is passed over heated copper oxide (CuO), the black coating on the surface turns brown as the reverse reaction takes place and copper is obtained. The second reaction is called oxidation-reduction reaction or redox reaction.

Answer 2

Answer:

Explanation:

Why black coating on the surface of copper oxide turns brown when hydrogen gas is passed over heated copper oxide?

If hydrogen gas is passed over heated copper oxide (CuO), the black coating on the surface turns brown as the reverse reaction takes place and copper is obtained. ... The hydrogen is gaining oxygen and is being oxidised.In other words, one reactant gets oxidised while the other gets reduced.