Q109 / 200 · MHT CET - Medical 2026 (24 April Shift 1) · Chemistry
Which of the following exhibits $-$I effect?
- A$-\text{C}(\text{CH}_3)_3$
- Correct answerB$-\text{NO}_2$
- C$-\text{C}_2\text{H}_5$
- D$-\text{CH}_3$
Solution
The inductive effect refers to the polarization of a $\sigma$-bond due to the electron-withdrawing or electron-donating nature of adjacent groups or atoms.
Groups that withdraw electrons more strongly than hydrogen exhibit a $-$I effect, while groups that donate electrons more strongly than hydrogen exhibit a $+$I effect.
Alkyl groups such as $-\text{CH}_3$, $-\text{C}_2\text{H}_5$, and $-\text{C}(\text{CH}_3)_3$ are electron-donating and show a $+$I effect.
The $-\text{NO}_2$ group contains highly electronegative oxygen and nitrogen atoms, making it a strong electron-withdrawing group. Therefore, it exhibits a strong $-$I effect.
Answer: $-\text{NO}_2$
Groups that withdraw electrons more strongly than hydrogen exhibit a $-$I effect, while groups that donate electrons more strongly than hydrogen exhibit a $+$I effect.
Alkyl groups such as $-\text{CH}_3$, $-\text{C}_2\text{H}_5$, and $-\text{C}(\text{CH}_3)_3$ are electron-donating and show a $+$I effect.
The $-\text{NO}_2$ group contains highly electronegative oxygen and nitrogen atoms, making it a strong electron-withdrawing group. Therefore, it exhibits a strong $-$I effect.
Answer: $-\text{NO}_2$
Hence, the correct answer is option: 'B'.