Question

Black copper oxide (heated) forms_________and copper metal when hydrogen gas is passed over it.​

Answer 1

Answer:

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 oxidized while the other gets reduced.

Explanation:

Answer 2

Answer:

When hydrogen gas is passed over heated copper oxide, then the black copper oxide is reduced and brown copper metal is obtained.

Explanation: