Question

Which one of the carbanions is the least stable?

• A.

  

• B.

  

• C.

  

• D.

  

Hint:

Carbanions are stabilised by electron-withdrawing groups (e.g., \( -\text{NO}_2 \), \( -\text{CHO} \)) and destabilised by electron-donating groups (e.g., \( -\text{CH}_3 \)).

Answer 1

The Correct Option is C

The stability of carbanions depends on the presence of electron-withdrawing or electron-donating groups attached to the carbon atom. - \( -\text{NO}_2 \) and \( -\text{CHO} \) are strong electron-withdrawing groups, which help to stabilise the negative charge on the carbanion. - \( -\text{CH}_3 \), being an electron-donating group, destabilises the negative charge on the carbanion. Thus, the carbanion in \( \text{CH}_2-\text{CH}_3 \) (which lacks electron-withdrawing groups) is the least stable. Final Answer: