The concentration of hydroxide ion in an aqueous solution at 25°C is 3.6 × 10⁻⁴ M. What is the concentration of the hydronium ion?

Answer 1

You must know that [H₃O⁺] x [OH-] = Kw = 1x10^-14

Substituting the know [OH-], we can solve for the [H³O⁺]

[H₃O⁺][3.6x10^-4] = 1x10^-14

[H₃O⁺] = 1x10^-14 / 3.6x10^-4

[H₃O⁺] = 2.8x10^-11 M