The hydronium ion concentration in an aqueous solution of is at 25°C. The hydroxide ion concentratio — Ionic Equilibrium Chemistry Question

💡 Solution & Explanation

At 25°C, the ionic product of water is $K_w = [\text{H}^+][\text{OH}^-] = 1.0 \times 10^{-14}$. Given $[\text{H}_3\text{O}^+] = 2.0 \times 10^{-4}\text{ M}$, the concentration of hydroxide ions is $[\text{OH}^-] = \frac{1.0 \times 10^{-14}}{2.0 \times 10^{-4}} = 0.5 \times 10^{-10}\text{ M} = 5.0 \times 10^{-11}\text{ M}$.