Question

Chlorine reacts with water in presence of sunlight to liberate________

Answer 1

Decomposition of Hypochlorous acid:

• Water chlorination is the addition of chlorine or chlorine compounds to water. The chlorine water has a light yellow color.
• When chlorine water is exposed to sunlight, the chlorine (${\mathrm{Cl}}_2$) interacts with the water molecules and produces Hypochlorous acid ($\mathrm{HClO}$).

$\underset{\mathrm{Chlorine}\mathrm{gas}}{{\mathrm{Cl}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}\rightleftharpoons \underset{\mathrm{Hypochlorous}\mathrm{acid}}{\mathrm{HClO}\left(\mathrm{l}\right)}+\underset{\mathrm{Hydrochloric}\mathrm{acid}}{\mathrm{HCl}\left(\mathrm{l}\right)}$

• Further, this $\mathrm{HClO}$ decomposes into nascent oxygen ($\mathrm{O}$) and hydrochloric acid ($\mathrm{HCl}$) $\underset{\mathrm{Hypochlorous}\mathrm{acid}}{\mathrm{HClO}\left(\mathrm{l}\right)}\to \underset{\mathrm{Hydrochloric}\mathrm{acid}}{\mathrm{HCl}\left(\mathrm{l}\right)}+\underset{\mathrm{Nascent}\mathrm{oxygen}}{\left[\mathrm{O}\right]}$
• When chlorine water, which has a typical light yellow color, is exposed to sunlight, it creates colorless gas or changes color from light yellow to colorless.

Therefore, Chlorine reacts with water in presence of sunlight to liberate Oxygen gas.