A : Friedel-crafts alkylation of benzene occurs in the presence of Lewis acid.
R : The function of Lewis acid to generate electrophile.

Options

A. If both Assertion & Reason are true and 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 analyze the assertion and reason provided in the question, we will break down the concepts step by step.

### Step 1: Understanding the Assertion
**Assertion (A):** Friedel-Crafts alkylation of benzene occurs in the presence of Lewis acid.

- **Explanation:** Friedel-Crafts alkylation is a reaction where an alkyl group is introduced to a benzene ring. This reaction requires a catalyst, which is typically a Lewis acid (like AlCl3). The Lewis acid helps in the formation of a more reactive electrophile from the alkyl halide.

### Step 2: Understanding the Reason
**Reason (R):** The function of Lewis acid is to generate electrophile.

- **Explanation:** Lewis acids are electron pair acceptors. In the context of Friedel-Crafts alkylation, the Lewis acid interacts with the alkyl halide to create a carbocation (the electrophile) that can then react with the benzene ring. The generation of this electrophile is crucial for the reaction to proceed.

### Step 3: Evaluating the Truth of Assertion and Reason
- Both the assertion and reason are true statements. Friedel-Crafts alkylation indeed requires a Lewis acid, and the primary role of the Lewis acid in this reaction is to generate the electrophile.

### Step 4: Checking if the Reason Explains the Assertion
- The reason provided accurately explains the assertion. The presence of the Lewis acid is necessary to generate the electrophile that will react with benzene, thus validating the assertion.

### Conclusion
- Both the assertion (A) and reason (R) are true, and the reason is the correct explanation of the assertion.

### Final Answer
- **Assertion (A): True**
- **Reason (R): True**
- **Explanation:** The function of the Lewis acid in Friedel-Crafts alkylation is to generate the electrophile necessary for the reaction to occur.

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