Calculate the concentration of hydronium and hydroxide ions in a 0.050 M solution of nitric acid.

[H₃O⁺] = 0.05 M & [OH⁻] = 2.0 x 10⁻¹³.

Explanation:

HNO₃ is completely ionized in water as:

HNO₃ + H₂O → H₃O⁺ + NO₃⁻.

The concentration of hydronium ion is equal to the concentration of HNO₃:

[H₃O⁺] = 0.05 M.

∵ [H₃O⁺][OH⁻] = 10⁻¹⁴.

∴ [OH⁻] = 10⁻¹⁴/[H₃O⁺] = 10⁻¹⁴/0.05 = 2.0 x 10⁻¹³.