A solution has [oh-] = 2.3*10-2 m. use the ion product constant of water kw=[h3o+][oh-] to find the [h3o+] of the solution.

Answer is: concentration of hydronium ions is 4.35·10⁻¹³ M.

[OH ⁻] = 2.3·10⁻² M; equilibrium concentration of hydroxide ions.

The Kw (the ionic product for water) at 25°C is 1·10 ⁻¹⁴ mol²/dm⁶ or 1·10⁻¹⁴ M².

Kw = [H ₃O⁺] · [OH⁻].

[H ₃O⁺] = Kw : [OH⁻].

[H ₃O⁺] = 1·10⁻¹⁴ M² : 2.3·10⁻² M.

[H ₃O⁺] = 4.35·10⁻¹³ M.