NEET2026ChemistryChapterActual
Identify the correct decreasing order of acidic strength for the following substituted carboxylic acids.
Options
- ANC-CH₂COOH F-CH₂COOH Cl-CH₂COOH CH₃CH₂COOH
- BF-CH₂COOH NC-CH₂COOH Cl-CH₂COOH CH₃CH₂COOH
- CF-CH₂COOH Cl-CH₂COOH NC-CH₂COOH CH₃CH₂COOH
- DCH₃CH₂COOH Cl-CH₂COOH F-CH₂COOH NC-CH₂COOH
Correct answer
A. NC-CH₂COOH F-CH₂COOH Cl-CH₂COOH CH₃CH₂COOH
Step-by-step solution
The acidic strength of substituted carboxylic acids depends on the electron-withdrawing nature (-I effect) of the substituent attached to the -carbon. Electron-withdrawing groups stabilize the carboxylate anion formed after the loss of a proton, thereby increasing the acidic strength. The decreasing order of the -I effect for the given substituents is: - CN > - F > - Cl The methyl group ( - CH₃ ) in CH₃CH₂COOH exhibits an electron-donating +I effect, which destabilizes the carboxylate anion and decreases the acidic