Question

Use the given molar solubilities in pure water to calculate the Ksp for each compound. PbF₂ molar solubility of 5.63 x 10^-3 M. Can you please show me the steps to show this problem? I know what the answer to the problem is but I can't get the steps right to come to the right answer.

Answer 1

Given Molar solubility of PbF₂ is = S = 5.63x10^-3 M

PbF₂ ----> Pb²⁺ + 2F^-

1 mole of PbF₂ produces 1 mole of Pb²⁺ 2 moles of F^-

So solubility of Pb²⁺ = S & solubility of [F^-] = 2S

Solubility product constant , K_sp = [Pb²⁺][ 2F^- ]²

                                                = S x (2S)²

                                                = 4S³

                                                = 4x(5.63x10^-3)³

                                                = 7.14x10^-7 M³