Chemistry - GOC Question with Solution | TestHub

Acid strength of substituted carboxylic acids increases with the strength of the -I effect and decreases with distance from the carboxyl group. Fluorine is more electronegative than chlorine, so a fluoro substituent withdraws more strongly, and the α position is closer to COOH than beta. α-fluorobutyric acid therefore stabilises its carboxylate best and has the highest Ka.