Question

The solubility product of lithium phosphate (Li3POA) is 3.2 x 10-9 at 259 C. What is the molar concentration of Li* ions in mol/L in an equilibrium mixture of lithium phosphate at 25 C?​

Answer 1

The concentration of Li+ is 0.0099 mol/L at 25C.

Step-by-step explanation:

First, we must write the solubility equation (I'm not sure if that's the correct term but oh well):

Li3PO4(s) ⇒ 3Li+(aq) + PO4 3- (aq)

From this equation, the final concentration of the lithium ions will be three times the final concentration of the phosphate ion. Let x be the concentration of phosphate. Then, the concentration of lithium will be 3x. We then have this equation: (3x)³(x) = 3.2*10^-9.

Solving for x, we have that x ≈ 0.0033. Thus, the concentration of Li+ is 3x = 0.0099 (2 significant figures) mol/L at 25C.