How does hydrogen reduce cupric oxide?

1 Answer
Sep 12, 2016

In fact hydrogen is being oxidized.

Explanation:

#stackrel(+II)" CuO"(s)+H_2(g) rarrstackrel0"Cu"(s) + H_2O(l)#.

Copper makes the redox transition, #Cu(II) rarr Cu(0)#. Dihydrogen makes the redox transiton, #stackrel(0)H_2 rarr stackrel(+I)H#.

Thus copper oxide formally gains 2 electrons to give copper metal, a true reduction, and hydrogen loses 1 electron upon oxidation to water.