Q.:- Identify the substances that are oxidized and the substances that are reduced in the following reactions:
(i) 4Na(s) + O2(g) –> 2Na2O(s)
(ii) CuO(s) + H2(g) –> Cu(s) + H2O(liq)
(i) Sodium (Na) is oxidized to Na2O.
(ii) CuO (Copper oxide) is reduced to Cu, while H2 gas is oxidized to H2O.