A : In esterification reaction , HCOOH is the most reactive acid among carboxylic acid .
R : Alcohol acts as nucleophile

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 solve the question, we need to analyze both the assertion (A) and the reason (R) provided.

### Step 1: Analyze the Assertion (A)
The assertion states: "In esterification reaction, HCOOH is the most reactive acid among carboxylic acids."

- **Explanation**: Esterification is a reaction where a carboxylic acid reacts with an alcohol to form an ester and water. The reactivity of carboxylic acids in esterification is influenced by the stability of the carbonyl carbon. In the case of formic acid (HCOOH), the carbonyl carbon is less hindered compared to other carboxylic acids that have larger alkyl groups. Larger alkyl groups can donate electron density through the +I effect, which reduces the positive character of the carbonyl carbon, making it less reactive. Therefore, HCOOH, having only a hydrogen atom, is indeed the most reactive carboxylic acid.

### Conclusion for Assertion (A):
The assertion is **true**.

### Step 2: Analyze the Reason (R)
The reason states: "Alcohol acts as a nucleophile."

- **Explanation**: In the esterification reaction, the alcohol (R-OH) has a lone pair of electrons on the oxygen atom, which allows it to act as a nucleophile. A nucleophile is a species that donates an electron pair to form a chemical bond. In this case, the oxygen in the alcohol attacks the electrophilic carbon of the carboxylic acid, leading to the formation of an ester.

### Conclusion for Reason (R):
The reason is also **true**.

### Step 3: Determine the Relationship Between A and R
Now we need to assess whether the reason explains the assertion.

- While both statements are true, the reason (alcohol acts as a nucleophile) does not explain why HCOOH is the most reactive acid. The reactivity of HCOOH is due to its structure and the lack of electron-donating alkyl groups, which is not addressed by the reason provided.

### Final Conclusion:
- Both the assertion and the reason are true, but the reason does not provide a correct explanation for the assertion.

### Answer:
The correct option is **2**: Both assertion and reason are true, but the reason is not the correct explanation of the assertion.

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