Question

Which of the following statements regarding different electronic effects in organic reactions is TRUE ?

• A. Hyperconjugation is a temporary electronic effect.
• B. -CN group show positive resonance effect.
• C. The effect of hyperconjugation is usually stronger than the inductive effect.
• D. The resonance hybrid is less stable than any of the resonance structures.

Hint:

Check each statement against the definitions of hyperconjugation, the cyano group effect and resonance stability.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
Electronic effects are either permanent (inductive, resonance, hyperconjugation) or temporary (electromeric).

Step 2: Check the Statements
(A) is false because hyperconjugation is a permanent effect.
(B) is false because the -CN group shows a negative resonance effect.
(D) is false because the resonance hybrid is more stable than any single resonance structure.

Step 3: Statement (C)
Hyperconjugation is generally a stronger effect than the inductive effect, as seen in the stability of alkenes and carbocations.

Step 4: Conclusion
Statement (C) is true.

Final Answer:
Hyperconjugation is usually stronger than the inductive effect. \[ \boxed{\text{(C) }\text{The effect of hyperconjugation is usually stronger than the inductive effect.}} \]