The correct order of decreasing acidity of the following aliphatic acids is

Question

Professor PC Thomas Classes · Answer

(a) : Acidic strength $\propto-I$ effect $\propto \frac{1}{+I}$ effect. Electron donating groups decrease the stability of carboxylate ion. Thus, the correct order of decreasing acidity is
$
\mathrm{HCOOH}>\mathrm{CH}_3 \mathrm{COOH}>\left(\mathrm{CH}_3\right)_2 \mathrm{CHCOOH}>\left(\mathrm{CH}_3\right)_3 \mathrm{CCOOH} .
$