Reduction of Metal Oxides

By Hydrogen: only the metals below Hydrogen in the reactivity series are reduced by using this method (mainly only CuO)

CuO (s) + H2 (g) -> Cu (s) + H2O (l)

By Carbon: only the metals below Carbon in the reactivity series are reduced by using this method

2 PbO (s) + C (s) -> 2 Pb (l) + CO2 (g)

By Carbon Monoxide: only metals below Carbon in the reactivity series are reduced by using this method

CuO (s) + CO (g) -> Cu(s) + CO2 (g)