Acids & Bases Chemistry Math Question 5

Question

In a 0.1 M solution of chlorous acid, what percentage of the acid is ionized to the chlorous anion, ClO₂^-? K_a = 1.1 x 10^-2

Answer 1

HClO2 ===> H⁺ + ClO₂^-

Ka = [H⁺][ClO₂^-]/[HClO₂]

1.1x10^-2 = (x)(x)/0.1-x

1.1x10^-3 - 1.1x10^-2x = x²

x² + 1.1x10^-2x - 1.1x10^-3 = 0

Use the quadratic equation to solve for x:

x = 0.028 = [H⁺] = [ClO₂^-]

Percent ionization = 0.018/0.1 (x100%) = 18% ionized