Question

The solubility product for Ir3PO4(s) is: Ksp = 2.74 times 10^-18. Determine what the molar solubility is of Ir3PO4 in water?

Answer 1

..........Ir3PO4 ==> 3Ir^^+ + [PO4]^3-

I............solid...........0.............0
C...........solid...........3x.............x
E............solid..........3x.............x
Ksp = (Ir^+)^3[PO4] = 2.74E-18.
Plug in the E line into the Ksp expression and solve for x = solubility of Ir3PO4 in mols/L.