The concentration of Mg²⁺ in seawater is 0.052 M. At what pH will 99% of the Mg²⁺ be precipitated as the hydroxide? (K_sp for Mg(OH)₂ = 8.9 × 10^-12)

Question

Quizplus · Accepted Answer

To precipitate 99% of Mg²⁺, the concentration of Mg²⁺ remaining in solution should be 1% of 0.052 M, which is 0.00052 M. Using the Ksp expression for Mg(OH)₂, [Mg²⁺][OH⁻]² = 8.9 × 10⁻¹², and substituting [Mg²⁺] = 0.00052 M, we solve for [OH⁻] and then calculate pH. The pH is approximately 10.12.

The Concentration of Mg2+ in Seawater Is 0

The Concentration of Mg²⁺ in Seawater Is 0