What is the molar solubility of Mg(OH)₂ in a basic solution with a pH of 12.50? K_spfor Mg(OH)₂ is 5.6 × 10^-1². A)1.8 × 10^-10 M B)5.6 × 10^-9 M C)2.4 × 10^-6 M D)1.1 × 10^-4 M

Question

Quizplus · Accepted Answer

To determine the molar solubility of Mg(OH)2 in a basic solution, we need to use the following equation:

Mg(OH)2(s) ⇌ Mg2+(aq) + 2OH-(aq)

The Ksp expression for this reaction is:

Ksp = [Mg2+][OH-]^2

Since the solution is basic with a pH of 12.50, we can assume that [OH-] = 10^-2.50 M = 3.2 × 10^-13 M.

Substituting into the Ksp expression gives:

5.6 × 10^-12 = [Mg2+](3.2 × 10^-13)^2

Solving for [Mg2+] gives:

[Mg2+] = 5.6 × 10^-9 M

Finally, since the stoichiometry of the reaction is 1:1 between Mg(OH)2 and Mg2+, the molar solubility of Mg(OH)2 is also 5.6 × 10^-9 M.

Therefore, the best choice is B, 5.6 × 10^-9 M.

What Is the Molar Solubility of Mg(OH)2 in a Basic

What Is the Molar Solubility of Mg(OH)₂ in a Basic