molar solubility?

Question

calculate the molar solubility of Ag2CO3 in water. at 25C, ksp=8.1 x 10^ -12

Answer 1

Assume that the molar solubility is s.

Then

.. .. .. .. .. .. Ag2CO3 <=> 2Ag+ +CO3-2
Dissolve .. .. .. s
Produce .. .. .. .. .. .. .. .. .. 2s .. .. .. s

Ksp = [Ag+]^2[CO3-2] = (2s)^2*s = 4s^3 =>
s= Cuberoot(Ksp/4) or ir you prefer
s= (Ksp/4)^(1/3) = ((8.1*10^-12)/4)^(1/3) = 1.27*10^-4 M