Question

Name the gas that bleaches a substance. Give the reaction involved?

Answer 1

Chlorine gas (Cl₂) bleaches colored substances permanently through oxidation in the presence of moisture.

Reaction Involved:

1. Chlorine reacts with water to form hydrochloric acid and hypochlorous acid:

\[\text{Cl}_2 + \text{H}_2\text{O} \longrightarrow \text{HCl} + \text{HOCl}\]

2. Hypochlorous acid (HOCl) is unstable and decomposes to release nascent oxygen ([O]):

\[\text{HOCl} \longrightarrow \text{HCl} + [\text{O}]\]

3. The nascent oxygen reacts with the colored substance to oxidize it into a colorless substance:

\[ \text{Colored substance} + [\text{O}] \longrightarrow \text{Colorless substance} \]