Conjugate Acid/Base Strength from Kₐ

Question

K_a for acetylsalicylic acid (aspirin), HC₉H₇O₄, is 3.00×10^-4.

K_a for benzoic acid, C₆H₅COOH, is 6.30×10^-5.

K_a for hypochlorous acid, HClO, is 3.50×10^-8.

What is the formula for the strongest conjugate base?

Answer 1

The weakest acid will have the strongest conjugate base, so with a K_a of 3.50 x 10^-8 HClO is the weakest acid, and its conjugate base is ClO^-.