Question

Find the number of hyperconjugation structures in the isopropyl carbocation.

• A. \(3\)
• B. \(6\)
• C. \(9\)
• D. \(12\)

Hint:

Count the alpha C-H bonds next to the positive carbon.

Answer 1

The Correct Option is B

Step 1: Draw the cation:
Isopropyl cation: $\text{CH}_3-\text{CH}^+-\text{CH}_3$.

Step 2: Count:
The carbons attached to the charged carbon are the two methyl carbons, each with three C-H bonds. These are the hyperconjugating bonds.

Step 3: Total:
$2\times3 = 6$ structures. For comparison, ethyl has 3 and tert-butyl has 9. The answer is option (B).

Final Answer:
Isopropyl cation has 6 hyperconjugative forms. \[ \boxed{\text{(B) }6} \]