Identify the substances that are oxidised and that are reduced in the following equation.

1. i) 4Na(s) + O₂(g) → 2Na₂O(s)
2. ii) CuO(s) + H₂(g) → Cu(s) + H₂O(l)

Solution:

The Sodium (Na) in the first equation is getting oxidized with the addition of Oxygen (O₂), and the Copper (Cu) in the second equation is reduced due to the addition of Hydrogen (H₂).