Calculate the molar solubility of aluminum phosphate in water given that K_sp = 1.3 × 10^-20.

Question

Quizplus · Accepted Answer

The solubility product (Ksp) of aluminum phosphate, AlPO4, is given as 1.3 × 10^-20. The dissolution of AlPO4 in water can be represented as: AlPO4(s) ⇌ Al^3+(aq) + PO4^3-(aq). From this equation, it's clear that the molar ratio of Al^3+ to PO4^3- is 1:1, meaning that the concentration of Al^3+ ions and PO4^3- ions in the solution will be the same at equilibrium. Let's denote the molar solubility of AlPO4 as S. Therefore, [Al^3+] = S and [PO4^3-] = S. Substituting these into the expression for Ksp gives: Ksp = [Al^3+][PO4^3-] = S^2. Solving for S, we get S = sqrt(Ksp) = sqrt(1.3 × 10^-20) = 1.1 × 10^-10 M, which matches choice A.

Calculate the Molar Solubility of Aluminum Phosphate in Water Given