Ascorbic acid (vitamin C) is a diprotic acid, . What is the pH of a solution? The acid ionization co — Ionic Equilibrium Chemistry Question

💡 Solution & Explanation

Because $K_{a1} \gg K_{a2}$, the first dissociation dictates the pH. $[\text{H}^+] \approx \sqrt{K_{a1} C} = \sqrt{9.0 \times 10^{-5} \times 0.10} = \sqrt{9.0 \times 10^{-6}} = 3.0 \times 10^{-3}\text{ M}$. $\text{pH} = -\log(3.0 \times 10^{-3}) = 3 - \log 3 = 3 - 0.48 = 2.52$.