Question

Which from following groups exhibits +I effect?

• A. $\text{-COOR}$
• B. $\text{-COOH}$
• C. $-\text{C}_2\text{H}_5$
• D. $-\text{NO}_2$

Hint:

Rule: Alkyl groups $\rightarrow$ +I
Electron withdrawing groups $\rightarrow$ -I

Answer 1

The Correct Option is C

Concept: Inductive effect depends on electron donating or withdrawing nature of groups.
• Alkyl groups $\rightarrow$ +I (electron donating)
• Electron withdrawing groups $\rightarrow$ -I

Step 1: Identify groups.
• $-\text{COOH}$, $-\text{COOR}$, $-\text{NO}_2$ $\rightarrow$ electron withdrawing (-I)
• $-\text{C}_2\text{H}_5$ $\rightarrow$ electron donating (+I)

Step 2: Conclusion.
Thus, ethyl group shows +I effect. Final Answer: Option (C)