A 7.0 × 10^-3 M aqueous solution of Ca(OH)₂ at 25.0°C has a pH of __________. A)12.15 B)1.85 C)1.4 × 10^-2 D)7.1 × 10^-13 E)11.85

Question

Quizplus · Accepted Answer

Ca(OH)₂ is a strong base and dissociates completely in water to produce 2 OH⁻ ions per formula unit. Therefore, [OH⁻] = 2 × 7.0 × 10⁻³ M = 1.4 × 10⁻² M. The pOH is calculated as -log(1.4 × 10⁻²) ≈ 1.85. Since pH + pOH = 14, the pH is 14 - 1.85 = 12.15.

A 70 × 10-3 M Aqueous Solution of Ca(OH)2 at 25

A 70 × 10^-3 M Aqueous Solution of Ca(OH)₂ at 25