Write balanced equations for the following reactions:
(a) reduction of copper oxide by hydrogen.
(b) reduction of iron (III) oxide by carbon monoxide.
(c) reduction of lead (II) oxide by carbon.

(a) On heating copper oxide in the presence of hydrogen gas, it gets reduced to copper metal and water.​
$$\begin{gathered} \mathrm{CuO}+{\mathrm{H}}_2\stackrel{\mathrm{Heat}}{\to }\mathrm{Cu}+{\mathrm{H}}_2\mathrm{O} \\ \mathrm{Copper}\mathrm{oxide}\mathrm{Hydrogen}\mathrm{gas}\mathrm{Copper}\mathrm{Water} \end{gathered}$$

(b) On heating iron (III) oxide in the presence of a reducing agent such as carbon monoxide, it reduces to iron and carbon dioxide gas is liberated in the process.​
$$\begin{gathered} {\mathrm{Fe}}_2{\mathrm{O}}_3+3\mathrm{CO}\stackrel{\mathrm{Heat}}{\to }2\mathrm{Fe}+3{\mathrm{CO}}_2 \\ \mathrm{Iron}\left(\mathrm{III}\right)\mathrm{oxide}\mathrm{Carbon}\mathrm{monoxide}\mathrm{Iron}\mathrm{Carbon}\mathrm{dioxide} \end{gathered}$$

(c) On heating lead (II) oxide with carbon as a reducing agent​, it gets reduced to lead and carbon monoxide gas is liberated in the process.​
$$\begin{gathered} \mathrm{PbO}+\mathrm{C}\stackrel{\mathrm{Heat}}{\to }\mathrm{Pb}+\mathrm{CO} \\ \mathrm{Lead}\left(\mathrm{II}\right)\mathrm{oxide}\mathrm{Carbon}\mathrm{Lead}\mathrm{Carbon}\mathrm{monoxide} \end{gathered}$$