MHT CET202613 April 2026Evening ShiftChemistryCarboxylic Acid DerivativesActual
Which is a weakest acid among the following ?
Options
- A( CH ₃)₂ CHCOOH
- BCH ₃ COOH
- CClCH ₂ COOH
- DCl ₃ CCOOH
Correct answer
A. ( CH ₃)₂ CHCOOH
Step-by-step solution
Acidic strength is directly proportional to the stability of the conjugate base. Electron-withdrawing groups ( -I effect) stabilize the carboxylate ion and increase acidic strength, while electron-donating groups ( +I effect) destabilize the carboxylate ion and decrease acidic strength. The +I effect of the isopropyl group ( CH ₃)₂ CH - is greater than that of the methyl group CH ₃- . Chlorine atoms exert a -I effect, which increases acidic strength. Thus, Cl ₃ CCOOH and ClCH ₂ COOH are stronger acids. Since ( CH ₃