When copper oxide is heated with hydrogen, copper metal and water are formed. What happens to the Hydrogen in this reaction?

CuO + H₂ → CuO + H₂O

Viewpoint 1 :
H₂ gain oxygen to form water. Hence, H₂ undergoes oxidation.

Viewpoint 2 :
The oxidation number of H increases from 0 (in H₂) to +1 (in H₂O). Hence, H₂ undergoes oxidation.

...... The answer is : 2. Oxidation

Redox reaction..... It's certainly not a decomposition reaction. They have only one reactant. Oxidation and reduction MUST occur simultaneously. There can't be one without the other.

+2-2 ........0.............0.......... +1-2 ..... oxidation states
CuO(s) + H2(g) --> Cu(s) + H2O(l)

Oxidation - increase in oxidation number
Reduction - decrease in oxidation number

Copper is reduced, hydrogen is oxidized.

The hydrogen combines wit the oxide = oxygen to form H2O = water.

IT FORMED WATER!!!!!!!!!!!!!!!