What is the action of litmus with aqueous chlorine? 

Explanation

### Step-by-Step Solution:

1. **Understanding Litmus Paper**: Litmus paper is a pH indicator used to test the acidity or basicity of a solution. Blue litmus paper turns red in acidic solutions, while red litmus paper remains red in acidic solutions but turns blue in basic solutions.

2. **Action of Aqueous Chlorine**: Aqueous chlorine (Cl₂ dissolved in water) is known to be acidic in nature. When it comes in contact with litmus paper, it will react with the dyes present in the litmus paper.

3. **Effect on Blue Litmus Paper**: When blue litmus paper is dipped in aqueous chlorine, it turns red. This indicates that the solution is acidic.

...