Question

The correct decreasing order for acid strength is:
1. NO₂CH₂ COOH > NCCH₂ COOH > FCH₂ COOH > ClCH₂ COOH
2. FCH₂ COOH > NCCH₂ COOH > NO₂CH₂ COOH > ClCH₂ COOH
3. NO₂H₂ COOH > FCH₂ COOH > CNCH₂ COOH > ClCH₂ COOH
4. CNCH₂ COOH > O₂NCH₂ COOH > FCH₂ COOH > CICH₂ COOH

Answer 1

Correct Answer - Option 1 : NO₂CH₂ COOH > NCCH₂ COOH > FCH₂ COOH > ClCH₂ COOH

Concept:

All the given compounds are α-monosubstituted acetic derivatives and the α-substitution have been made by strong-I group/atoms. More powerful the –I group stronger will be the acid.

-I power of different groups is as follows:

-NO > -CN > -F > -Cl.

Thus, the correct decreasing order for acid strength is:

NO₂CH₂ COOH > NCCH₂ COOH > FCH₂ COOH > ClCH₂ COOH