If the concentration of Pb2+ is found to be 2.3 x 10-9 mol/L in a saturated solution of Pb3(PO4)2, what is the Ksp of Pb3(PO4)2 ?

This is my work thus far it is as far as I could get:

Ksp = [Pb2+] [Pb3(PO4)2]
= [2.3 x 10-9 mol/L][Pb3(PO4)2]

Try this:

Ksp = [Pb2+]^3 [PO4]^2
= (2.3E-9)^3 (2/3 * 2.3E-9)^2
= 4/9 * (2.3E-9)^5

Hardly soluble stuff. Notice if the Pb ion concentration is x, then the PO4 ion has to be 2/3 x.....from the ratios in the formula.

To find the Ksp of Pb3(PO4)2, you need to use the concentration of Pb2+ in the saturated solution. However, you don't have the concentration of Pb3(PO4)2.

To calculate the Ksp, you need to know the molar solubility (the maximum amount of the compound that can dissolve in a solvent) or the solubility product constant expression (Ksp) for Pb3(PO4)2.

The balanced chemical equation for the dissolution of Pb3(PO4)2 is:

3Pb3(PO4)2 ⇌ 6Pb2+ + 2PO4^3-

From the equation, you can see that for every 3 moles of Pb3(PO4)2 that dissolve, 6 moles of Pb2+ and 2 moles of PO4^3- are obtained.

The solubility product expression for Pb3(PO4)2 is:

Ksp = [Pb2+]^6 [PO4^3-]^2

Since you know the concentration of Pb2+ in the saturated solution (2.3 x 10^-9 mol/L), you can substitute it into the solubility product expression:

Ksp = [(2.3 x 10^-9 mol/L)^6] [PO4^3-]^2

However, to fully calculate the Ksp, you need to know the concentration of PO4^3- in the solution, which you haven't provided.

Please provide the concentration of PO4^3- in the solution, or if it's not given, you won't be able to calculate the Ksp without additional information.