The value of Ksp for CuI is 1 x 10^-12. What is the solubility for CuI?

Question

somehow I couldnt get an answer of this: 1.9 x 10^-4 g/L

Answer 1

CuI ----- Cu +1  + I-

a small amount of the solid will dissolve ( X ) to yield X amounts of Cu+1 and X amounts of I-

so the Ksp 1 X x 10^-12 = [x][x]   x = formal solubility = 1x 10^-6 moles per liter..CuI has a mass of 190.55 grams/moles  so

190.55 grams/mole X 1X 10^-6 moles = 1.906 X 10^-4 grams /liter

Answer 2

Ksp = [Cu]*[I]

Since the [Cu] = [I], then [Cu] = the square root of Ksp = 10^-6 moles per liter.

The molecular weight of CuI is 190.45 g/mole, so:

190.45 * 10^-6 = 1.9 x 10^-4 grams/liter