Reduction of alumina (Al2O3) to Al cannot be achieved by carbon reduction. As aluminium has greater reactivity with oxygen than carbon and hence cannot be reduced by carbon. So, electrometallurgy (Hall-Heroult process) is used to get Al. 2Al2O3(I)+3C⟶4Al+3CO2 Rest oxides can be reduced by coke as follows Fe2O3+3C⟶2Fe+3CO Cu2O+C⟶2Cu+CO ZnO+C