Explain the following in terms of gain

solution:
(a) Oxidation is the gain of oxygen.

For example,





In equation (i), $\mathrm{H}_{2}$ is oxidized to $\mathrm{H}_{2} \mathrm{O}$ and in equation (ii), $\mathrm{Cu}$ is oxidised to $\mathrm{CuO}$.

(b) Reduction is the loss of oxygen.

For example,





In equation (i), $\mathrm{CO}_{2}$ is reduced to $\mathrm{CO}$ and in equation (ii), $\mathrm{CuO}$ is reduced to $\mathrm{Cu}$.