Calculate the molar solubility of MX2 (Ksp=0.0000011) in 0.085 M NaX. Enter your answer as a decimal with two significant figures

Answer 1

I assume M is divalent and X is monivalent.
..........................MX2==> M^2+ + 2X^-
I........................solid.........0...........0
C.......................solid.........x...........2x
E........................solid........x...........2x

..................NaX==> Na^+ + X^-
I............0.085M.........0..........0.....
C...........-0.085........0.085.....0.085
E..............0............0.085.......0.085

Ksp = 1.1E-6 = (M^2+)(X^-)^2
Substitute the numbers.
(M^2+) from the above = x
(X^-) from the above = 2x from MX2 solubility and 0.085 from NaX so total is 2x + 0.085.
Ksp = 1.1E-6 = (x)(2x+0.085)^2
Solve for x = solubility of MX2 in mols/L.