Question

Which of the following acids is the weakest acid?


hypochlorous acid, Kₐ = 3.5 × 10⁻⁸

nitrous acid, Kₐ = 4.5 × 10⁻⁴

acetic acid, Kₐ = 1.8 × 10⁻⁵

hydrogen peroxide, Kₐ = 2.4 × 10⁻¹²

Answer 1

Answer: The strongest acid is the acid that dissociates with release of a proton to the largest degree. Ka of an acid is the measure of the equilibrium of association/dissociation of an acid in solution. The larger the Ka, the larger the degree of dissociation and the stronger the acid. Vice versa, the weakest acid will have the smallest Ka. Among the proposed , the smallest Ka is 2.4•10^-12. Therefore, the weakest acid is hydrogen peroxide.