What is the chromium ion concentration for a saturated solution of Cr(OH)₃ if the K_sp for Cr(OH)₃ is 6.7 × 10^-31? A)8)19 × 10^-16 M B)1)26 × 10^-8 M C)2)17 × 10^-8 M D)3)76 × 10^-8 M

Question

Quizplus · Accepted Answer

The solubility product expression for Cr(OH)₃ is Ksp = [Cr³⁺][OH⁻]³. Let the solubility of Cr(OH)₃ be s, then [Cr³⁺] = s and [OH⁻] = 3s. Substituting into the Ksp expression gives Ksp = s(3s)³ = 27s⁴. Solving for s using Ksp = 6.7 × 10⁻³¹ results in s ≈ 1.26 × 10⁻⁸ M.

What Is the Chromium Ion Concentration for a Saturated Solution