The Question is from neet-chemistry organic-chemistry-basics , and it was created by the author P SRAVAN KUMAR

Question

Which of the following carbocations is MOST stabilized by hyperconjugation?

P SRAVAN KUMAR · Accepted Answer

## CORE INFORMATION
✓ **Answer**: D
## CONCEPT FRAMEWORK
 **Primary Concept**: Hyperconjugation in carbocations
 **Related Topics**: Carbocation stability, inductive effect, resonance
 **Prerequisites**: Understanding of carbocation structure, sigma bonds, and orbital overlap.
## SOLUTION PATHWAY
**Given Information**:
  Four carbocations: $CH_3^+$, $CH_3CH_2^+$, $(CH_3)_2CH^+$, $(CH_3)_3C^+$
  The question asks for the most hyperconjugatively stabilized carbocation.
**Method & Steps**:
 1. Understand Hyperconjugation: Hyperconjugation is a stabilizing interaction between a filled σ-bonding orbital and an empty p-orbital.  The more alkyl groups attached to the carbocation carbon, the more C-H sigma bonds are available for hyperconjugation.
  Reasoning: Each C-H bond adjacent to the positively charged carbon can donate electron density to the empty p-orbital of the carbocation, stabilizing it.
  Formula/Rule: No specific formula, but understanding the concept is key.
 2. Analyze each carbocation:
  $CH_3^+$: No alkyl groups, no hyperconjugation.
  $CH_3CH_2^+$: One alkyl group (methyl), 3 C-H bonds available for hyperconjugation.
  $(CH_3)_2CH^+$: Two alkyl groups (methyl), 6 C-H bonds available for hyperconjugation.
  $(CH_3)_3C^+$: Three alkyl groups (methyl), 9 C-H bonds available for hyperconjugation.
  Working:  The number of α-C-H bonds (bonds on carbons directly attached to the positively charged carbon) determines the extent of hyperconjugation.
  Key Point: More α-C-H bonds lead to greater hyperconjugative stabilization.
 3. Determine the most stabilized carbocation:
  Result: $(CH_3)_3C^+$ has the most α-C-H bonds (9), therefore it experiences the greatest hyperconjugative stabilization.
  Verification: The stability order of carbocations is tertiary > secondary > primary > methyl, which aligns with the number of hyperconjugative interactions.
 ## OPTION ANALYSIS
A :x: $CH_3^+$ has no hyperconjugation.
B :x: $CH_3CH_2^+$ has less hyperconjugation than others.
C :x: $(CH_3)_2CH^+$ has less hyperconjugation than $(CH_3)_3C^+$.
D ✓: $(CH_3)_3C^+$ has the most hyperconjugation due to 9 α-C-H bonds, making it the most stable.
 ## LEARNING AIDS
 **Common Mistakes**:
  1.Confusing hyperconjugation with inductive effect: While both stabilize carbocations, hyperconjugation involves orbital overlap, while inductive effect is based on electron-withdrawing/donating ability of groups.
  2.Incorrectly counting α-C-H bonds:  Carefully identify the carbons directly attached to the positive charge and count the C-H bonds on those carbons only.
 **Quick Tips**:
  1.Remember the stability order of carbocations: tertiary > secondary > primary > methyl.
  2.Focus on the number of α-C-H bonds to quickly determine the extent of hyperconjugation.

P SRAVAN KUMAR · Answer

CH3+

P SRAVAN KUMAR · Answer

CH3CH2+

P SRAVAN KUMAR · Answer

(CH3)2CH+

P SRAVAN KUMAR · Answer

The correct Option is "(CH3)3C+"

NEET Chemistry Organic Chemistry: Some basic principles and techniques MCQs

Select Topic

Question Tags

Question Tags

Question Tags

Question Tags

Question Tags

Question Tags

Question Tags

Question Tags

Question Tags

Question Tags

NEET Subjects

Our Bots

Company