Chemistry Math Question

Question

In a 0.05 M solution of chlorous acid, what percentage of the acid is ionized to the clorous anion, ClO₂^-? K_a = 1.1 x 10^-2

Answer 1

Chlorous acid = HClO₂

HClO₂ <==> H⁺ + ClO₂^-

Ka = 1.1x10^-2 = [H⁺][ClO₂^-] / [HClO₂]

1.1x10^-2 = (x)(x) / 0.05 - x

x² = 5.5x10^-4 - 1.1x10^-2 x

x² + 1.1x10^-2x - 5.5x10^-4 = 0

x = 0.0186 M = [H⁺] = [ClO₂^-]

% ionization = 0.0186 / 0.05 (x100%) = 37.2% ionized