Chemistry molar solubility, common ion effect

Question

Calculate the molar solubility of Ca3(PO4)2

{ ksp= 1.99x10^-29} in a solution containing 0.325 M K3PO4 ?

(To the tutor who helped me with this problem with me last time, I think some of your calculations were incorrect. If the common ion is the PO4, then wouldn’t the 0.325 M take place within the Ca3(PO4)2? Inside the bracket of PO4.

making Ca3(PO4)2 <<<< 3Ca^+2 + 2PO4^-

ksp = [Ca^+2]^3 [PO4^-3]^2

ksp =(x)^3 (0.325)^2

1.99x 10^-29 = (x)^3 (0.325)^2

and then solve from there ? )

Answer 1

@Kim W. Yes, you are correct. In the previous answer, I didn't notice the presence of 0.325 M PO₄^3- and solved for the solubility in pure water.