Question

What is the colour change when copper oxide reacts with hydrogen and turns into copper???

Answer 1

Heated copper metal reacts with oxygen to form the black copper oxide. The copper oxide can then react with the hydrogen gas to form the copper metal and water.

Answer 2

Answer:

Black ⇒ Reddish brown

Explanation:

When copper oxide reacts with hydrogen and turns into copper the black color of copper (II) oxide changes to the reddish brown color of copper metal.

Chemical Reactions involved are:

2Cu(s) + O₂(g) → 2CuO(s)               { oxidation of Copper metal }

CuO(s) + H₂(g) → Cu(s) + H₂O(l)      {reduction of Copper (II) oxide }