In the following questions, a statement of assertion (A) is following by a statement of reason (R )
A: Dow's process is an example of nucleophillic substitution reaction.
R : In this process, benzyne is formed as an intermediate.

Options

A. If both Assertion & Reason are the reason is the correct explanation of the assertion, then mark (1).
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark(2).
C. If Assertion is true statement but Reason is false , then mark (3)
D. If both Assertion and Reason are false statements, then mark (4)

Answer

To solve the assertion-reason question regarding Dow's process, we will analyze both the assertion (A) and the reason (R) step by step.

### Step 1: Understanding the Assertion
**Assertion (A):** Dow's process is an example of a nucleophilic substitution reaction.

- **Explanation:** Dow's process is a method used to synthesize phenol from haloarenes, specifically chlorobenzene. In this process, chlorobenzene reacts with aqueous potassium hydroxide (KOH) at elevated temperatures (around 433 K). During this reaction, the chlorine atom (a leaving group) is replaced by a hydroxyl group (OH), which is characteristic of nucleophilic substitution reactions.

### Step 2: Understanding the Reason
**Reason (R):** In this process, benzyne is formed as an intermediate.

- **Explanation:** In the Dow's process, the reaction proceeds through the formation of an intermediate known as benzyne. When KOH is added to chlorobenzene, the hydroxide ion (OH-) acts as a nucleophile and attacks the hydrogen atom on the benzene ring. This results in the formation of a pi bond and the elimination of the chlorine atom, leading to the formation of benzyne as an intermediate. The benzyne can then react with another nucleophile, such as OH-, to form phenol.

### Step 3: Evaluating the Truth of Assertion and Reason
- **Is Assertion (A) True?** Yes, Dow's process is indeed a nucleophilic substitution reaction.
- **Is Reason (R) True?** Yes, benzyne is formed as an intermediate in this process.

### Step 4: Analyzing the Relationship Between Assertion and Reason
- **Does the reason (R) correctly explain the assertion (A)?** While both statements are true, the reason does not serve as the correct explanation for the assertion. The assertion is based on the overall process of nucleophilic substitution, while the reason focuses on the intermediate formed during the reaction.

### Conclusion
Both the assertion and the reason are true, but the reason is not the correct explanation for the assertion. Therefore, the correct answer is that both statements are true, but the reason does not explain the assertion.

### Final Answer
- **Assertion (A): True**
- **Reason (R): True**
- **Correct Explanation: No**