Identify the substances that are oxidised and the substances that are reduced in the following reactions. (a) 4Na (s) + O2 (g) → 2Na2O (s) (b) CuO (s) + H2 (g) → Cu (s) + H2O (l)
(a) Sodium (Na) is oxidised as it gains oxygen and oxygen gets reduced. (b) Copper oxide (CuO) is reduced to copper (Cu) while hydrogen (H2) gets oxidised to water (H2O).
