Question

The bleaching action of chlorine is due to

• A. Reduction
• B. Hydrogenation
• C. Chlorination
• D. Oxidation

Answer 1

The Correct Option is D

The question asks us about the bleaching action of chlorine. To understand why the correct answer is "Oxidation," let's delve into the chemistry behind the process.

Understanding the Bleaching Action of Chlorine

Chlorine is a powerful bleaching agent, and its action primarily relies on its ability to oxidize. Bleaching is the process by which a substance loses its color. Chlorine, when dissolved in water, forms hypochlorous acid (HOCl), which is a strong oxidizing agent. This can be represented by the following reaction:

Cl_2 + H_2O \rightarrow HCl + HOCl

The hypochlorous acid then reacts with the colored compounds, oxidizing them. The general effect of oxidation in bleaching is the destruction of chromophores (color-producing parts of molecules), which effectively removes color.

Choice Analysis

1. Reduction: This is the gain of electrons and is not the mechanism by which chlorine bleaches. Therefore, this option is incorrect.
2. Hydrogenation: This involves the addition of hydrogen, which is not relevant to the bleaching action of chlorine. Hence, this option is incorrect.
3. Chlorination: This is the addition of chlorine to a substance, which can occur but is not the primary mechanism of bleaching by chlorine. Thus, this option is incorrect.
4. Oxidation: This is the correct answer as the bleaching action of chlorine is due to its ability to oxidize other substances, breaking down chromophores and removing colors.

In conclusion, the bleaching action of chlorine is due to oxidation, as it involves the chemical process of oxidizing the colored substances, turning them colorless.