Assertion : Pentan-2-one and pentan-3-one can be distinguished by iodoform test.
Reason : Only methylketines take part in iodoform reaction.

Options

A. If both assertion and reason are correct and reason is correct explanation for assertion.
B. If both assertion and reason are correct and reason is not correct explanation for assertion.
C. If assertion is correct but reason is incorrect.
D. If assertion as well as reason are both incorrect.

Explanation

To solve the question regarding the assertion and reason about pentan-2-one and pentan-3-one in relation to the iodoform test, we can break it down step-by-step as follows:

### Step 1: Understand the Iodoform Test
The iodoform test is a chemical reaction used to identify the presence of methyl ketones (ketones with the structure CH3C(=O)R, where R can be any alkyl group). When a methyl ketone reacts with iodine in the presence of a base (like sodium hydroxide), it produces iodoform (CHI3) and a carboxylic acid.

**Hint:** Recall that the iodoform test specifically identifies methyl ketones.

### Step 2: Identify the Structures of Pentan-2-one and Pentan-3-one
- **Pentan-2-one**: The structure is CH3-CO-CH2-CH2-CH3. Here, the carbonyl group (C=O) is at the second carbon, and it has a methyl group (CH3) adjacent to it.
- **Pentan-3-one**: The structure is CH3-CH2-CO-CH2-CH3. In this case, the carbonyl group is at the third carbon, and it does not have a methyl group adjacent to it.

**Hint:** Draw the structures to visualize the positions of the carbonyl groups.

### Step 3: Determine if Each Compound is a Methyl Ketone
- **Pentan-2-one** has a methyl group adjacent to the carbonyl group, making it a methyl ketone. Therefore, it will undergo the iodoform test.
- **Pentan-3-one** does not have a methyl group adjacent to the carbonyl group, so it is not a methyl ketone and will not undergo the iodoform test.

**Hint:** Identify the presence of the methyl group next to the carbonyl group to determine if it is a methyl ketone.

### Step 4: Evaluate the Assertion
The assertion states that pentan-2-one and pentan-3-one can be distinguished by the iodoform test. Since pentan-2-one can undergo the iodoform test while pentan-3-one cannot, the assertion is correct.

**Hint:** Check if the compounds can be differentiated based on their ability to react in the iodoform test.

### Step 5: Evaluate the Reason
The reason states that only methyl ketones take part in the iodoform reaction. This statement is also correct because only compounds with a methyl group adjacent to the carbonyl group will react in this manner.

**Hint:** Confirm that the reason accurately explains why the assertion is true.

### Conclusion
Both the assertion and reason are correct, and the reason provides a correct explanation for the assertion. Therefore, the correct answer is that both the assertion and reason are correct, and the reason is the correct explanation for the assertion.

### Final Answer
Both assertion and reason are correct, and the reason is the correct explanation for the assertion.

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