A saturated aqueous solution of calcium hydroxide has a pH of 12.25.What is the [Ca²⁺] in such a solution? A)0.018 B)5.6 × 10^-13 C)2.3 × 10^-5 D)0.035 E)8.9 × 10^-3

Question

Quizplus · Accepted Answer

The pH of 12.25 corresponds to a pOH of 1.75, giving [OH⁻] = 10^(-1.75) = 0.018 M. Since Ca(OH)₂ dissociates into one Ca²⁺ and two OH⁻ ions, [Ca²⁺] = [OH⁻]/2 = 0.018/2 = 0.009 M, which is approximately 8.9 × 10⁻³ M.

A Saturated Aqueous Solution of Calcium Hydroxide Has a PH