Question

If the concentration of Pb^2+ is known to be roughly 2.1 x 10 to the power of -9 mol/L within a saturated solution of Pb(PO4)2, calculate the Ksp of Pb3(PO4)2?

Answer 1

Show me what you know and tell me what you don't understand. Start by writing the solubility equation.

Answer 2

Pb3(PO4)2 = 3 Pb + 2 PO4 = (2.3 x 10-9 )^3 (2.3 x 10-9 )^2 = 6.43 X 10^-44

Answer 3

If (Pb^+2) = 2.1 x 10^-9, then (PO4^-3) = 2/3 x (2.1 x 10^-9), and
Ksp = (2.1 x 10^-9)^3*[(2/3)* 2.1 x 10^-9]^2??