In a solution of pure water, the autoionization of water can be expressed by the following: H2O(l) ⇌ H+(aq) + OH−(aq) The equilibrium constant for the ionization of water, Kw, is called the ion-product constant of water. In pure water at 25 °C, Kw has a value of 1.0 × 10−14. The dissociation of water gives one H+ ion and one OH− ion and thus their concentrations are equal. The concentration of each is 1.0 × 10−7 M. Kw = [H+][OH−] Kw = (1.0 × 10-7)(1.0 × 10-7) = 1.0 × 10-14 [H+][OH−] = 1.0 × 10-14 A solution has a [OH−] = 4.2 × 10−8 M at 25 °C. What is the [H+] of the solution? Answer 2.4 × 10−15 M 2.4 × 10−6 M 2.4 × 10−7 M 4.2 × 106 M I don't know yet