Chemistry - GOC Question with Solution | TestHub

The second carboxyl group withdraws inductively and stabilizes the monoanion. Its effect falls with distance. Oxalic acid (III) has adjacent $\mathrm{COOH}$ groups, then malonic (I), succinic (IV), and glutaric acid (II). The first-ionization acidity order is $\mathrm{III}$ > $\mathrm{I}$ > IV > $\mathrm{II}$.