Question

Define photo chemical reaction.

Answer 1

Photochemical reaction - A reaction that occurs with the absorption of light energy is called a photochemical reaction.

Example - Reaction of hydrogen and chlorine form hydrochloric acid in the presence of sunlight.

$$\begin{gathered} {\mathrm{H}}_2+{\mathrm{Cl}}_2\stackrel{\mathrm{sunlight}}{\to }2\mathrm{HCl} \\ \mathrm{Hydrogen}\mathrm{Chlorine}\mathrm{Hydrochloric}\mathrm{acid} \end{gathered}$$