Question

Which among the following carbocation is most reactive?

• A. \( (\text{CH}_3)_3 \text{C}^+ \)
• B. \( (\text{CH}_3)_2 \text{C}^+ \)
• C. \( \text{CH}_3^+ \)
• D. \( \text{CH}_3 - \text{CH}_2^+ \)

Hint:

Carbocation stability increases with the number of alkyl groups attached to the positively charged carbon. Tertiary carbocations are the most stable.

Answer 1

The Correct Option is A

Step 1: Understanding carbocation stability.
The stability of a carbocation determines its reactivity. A more stable carbocation is less reactive, while an unstable carbocation is more reactive. The stability increases with more alkyl groups, as they donate electron density to the positive charge.

Step 2: Analyzing the options.
(A) \( (\text{CH}_3)_3 \text{C^+ \):} This is a tertiary carbocation, which is the most stable and thus the least reactive.
(B) \( (\text{CH}_3)_2 \text{C^+ \):} This is a secondary carbocation, which is less stable and more reactive than a tertiary carbocation.
(C) \( \text{CH}_3^+ \): This is a methyl carbocation, the least stable and most reactive.
(D) \( \text{CH}_3 - \text{CH}_2^+ \): This is a primary carbocation, which is also less stable and more reactive.

Step 3: Conclusion.
The correct answer is (A) \( (\text{CH}_3)_3 \text{C^+ \)} because tertiary carbocations are the most stable and thus the least reactive.