Assertion (A) Addition reaction of water to but-1-ene in acidic medium yields butan-1-ol.
Reason (R) Addition of water in acidic medium proceeds through the formation of primary carbocation.

Options

A. if both assertioon and reason are true and reason is the corrct explanation of assertion.
B. If both assertion and reason are ture but reason is not the corrcet explanation of assertion.
C. If assertion is true but reason is false .
D. if both assertion and reason are false.

Explanation

To solve the given question, we need to analyze both the assertion and the reason provided:

### Step 1: Understand the Assertion
The assertion states that the addition reaction of water to but-1-ene in acidic medium yields butan-1-ol.

- But-1-ene (C4H8) has the structure:
\[ CH_2=CH-CH_2-CH_3 \]
- When water is added to an alkene in the presence of an acid (H+), the reaction follows Markovnikov's rule, which states that the hydrogen atom from the acid will add to the carbon with more hydrogen atoms already attached, leading to the formation of a more stable carbocation.

### Step 2: Analyze the Reaction Mechanism
In the case of but-1-ene:
1. The double bond between the first two carbon atoms can react with H+ from the acid.
2. According to Markovnikov's rule, H+ will add to the first carbon (C1), resulting in the formation of a secondary carbocation at C2:
\[ CH_3-CH^+-CH_2-CH_3 \]
3. Water (H2O) will then attack this carbocation, leading to the formation of butan-2-ol (not butan-1-ol).

### Step 3: Conclusion on the Assertion
Since the product formed is butan-2-ol, the assertion that the reaction yields butan-1-ol is **incorrect**.

### Step 4: Understand the Reason
The reason states that the addition of water in acidic medium proceeds through the formation of a primary carbocation.

- As established, the reaction actually proceeds through the formation of a **secondary carbocation**, which is more stable than a primary carbocation.
- Therefore, the reason is also **incorrect**.

### Final Conclusion
Both the assertion and the reason are incorrect. Thus, the correct answer to the question is that both the assertion and the reason are false.

### Summary of the Answer
- **Assertion (A)**: Incorrect (yields butan-2-ol, not butan-1-ol).
- **Reason (R)**: Incorrect (proceeds through secondary carbocation, not primary).
- **Final Answer**: Both assertion and reason are false.

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