(A) : Chlorine acts as a bleaching agent in the presence of moisture
(R) : Chlorine forms hypochlorous acid in the presence of moisture.

Options

A. Both A & R are true, R is the correct explanation of A
B. Both A & R are true, R is not correct explanation of A
C. A is true, R is false
D. A is false, R is true

Answer

To solve the assertion and reason question regarding chlorine acting as a bleaching agent in the presence of moisture, we can break down the explanation step by step:

### Step 1: Understanding the Assertion
The assertion states that chlorine acts as a bleaching agent in the presence of moisture. This means that chlorine has the ability to lighten or remove color from substances when there is water present.

**Hint:** Consider what properties make a substance a bleaching agent.

### Step 2: Understanding the Reason
The reason given is that chlorine forms hypochlorous acid (HOCl) in the presence of moisture. This is a chemical reaction where chlorine gas reacts with water.

**Hint:** Recall the chemical reaction that occurs when chlorine interacts with water.

### Step 3: The Reaction
When chlorine (Cl₂) comes into contact with water (H₂O), it reacts to form hydrochloric acid (HCl) and hypochlorous acid (HOCl):
\[ \text{Cl}_2 + \text{H}_2\text{O} \rightarrow \text{HCl} + \text{HOCl} \]

**Hint:** Write down the balanced chemical equation to visualize the reaction.

### Step 4: The Role of Hypochlorous Acid
Hypochlorous acid (HOCl) is unstable and can decompose. This decomposition produces nascent oxygen (O), which is a highly reactive form of oxygen.

**Hint:** Think about how the instability of a compound can lead to the formation of reactive species.

### Step 5: Bleaching Action
The nascent oxygen produced from the decomposition of hypochlorous acid is what actually acts as the bleaching agent. It can react with colored compounds, breaking them down and resulting in a loss of color.

**Hint:** Consider how oxygen can interact with other substances to cause bleaching.

### Step 6: Conclusion
Both the assertion and the reason are true, and the reason correctly explains why chlorine acts as a bleaching agent in the presence of moisture.

**Final Statement:** Therefore, both the assertion (A) and the reason (R) are true, and R is the correct explanation of A.

### Summary of Steps:
1. Understand the assertion about chlorine as a bleaching agent.
2. Analyze the reason involving hypochlorous acid formation.
3. Write the chemical reaction of chlorine with water.
4. Discuss the instability of hypochlorous acid and its decomposition.
5. Explain the role of nascent oxygen in the bleaching process.
6. Conclude that both statements are true and related.