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Assertion: The relative ease of dehydrat...

Assertion: The relative ease of dehydration of alcohols following order:
Tretiary `gt ` secondary `gt` Primary
Reason : Formation of carbocation is the slowest step of reaction.

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.

Text Solution

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To solve the question regarding the assertion and reason about the dehydration of alcohols, let's break it down step by step: ### Step 1: Understanding the Assertion The assertion states that the relative ease of dehydration of alcohols follows the order: Tertiary > Secondary > Primary. This means that tertiary alcohols dehydrate more easily than secondary alcohols, which in turn dehydrate more easily than primary alcohols. **Hint:** Consider the stability of the intermediates formed during the dehydration process. ### Step 2: Analyzing Carbocation Stability The key to understanding the assertion is the stability of carbocations. Tertiary carbocations (formed from tertiary alcohols) are more stable than secondary carbocations, which are more stable than primary carbocations. The stability order is as follows: - Tertiary carbocation (most stable) - Secondary carbocation - Primary carbocation (least stable) **Hint:** Recall the concept of hyperconjugation and inductive effects that stabilize carbocations. ### Step 3: Relating Stability to Reaction Rate The rate of dehydration of alcohols is directly proportional to the stability of the carbocation formed. Since tertiary carbocations are the most stable, the dehydration of tertiary alcohols occurs more readily than that of secondary or primary alcohols. **Hint:** Think about how the stability of the carbocation affects the energy barrier for the reaction. ### Step 4: Understanding the Reason The reason provided states that the formation of carbocation is the slowest step of the reaction. This is indeed true, as the formation of the carbocation is the rate-determining step (RDS) in the dehydration process. If this step is slow, it will dictate the overall rate of the reaction. **Hint:** Identify the steps involved in the dehydration of alcohols and which step is the slowest. ### Step 5: Conclusion Both the assertion and the reason are correct. The assertion is correct because the order of dehydration is based on carbocation stability, and the reason is correct because the formation of the carbocation is indeed the slowest step in the reaction mechanism. **Final Answer:** - Assertion: True - Reason: True - The reason explains the assertion. ### Summary - Tertiary alcohols dehydrate more easily than secondary and primary due to the stability of the carbocation formed. - The formation of this carbocation is the slowest step in the reaction, confirming that both the assertion and reason are correct.
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