Answer to Question #327015 in General Chemistry for Favour

Question

Calculate the molar solubility of Al(OH)₃ in a solution that is slightly basic with a pH of 9.50.

Enter your response in scientific notation, e.g. enter 2E3 for 2000.

Answer 1

Al(OH)₃ = Al³⁺ + 3OH^-

K_sp[Al(OH)₃] = [Al³⁺] [OH^-]³ = 5.0 × 10^-33

[OH^-] = 10^-pOH = 10^-(14-pH) = 10^-(14-9.5) = 10^-4.5 = 3.16 × 10^-5 M

[Al³⁺] [OH^-]³ = S × (3.16 × 10^-5)³ = 5.0 × 10^-33

S = 1.58 × 10^-19 M