Darius A. answered • 03/02/21
Graduated Magna Cum Laude with BS in Chemistry/Biochemistry
The Ksp is the solubility constant for Ag2SO4. It will have the same setup or format as all expressions for K, which means that it's going to end up in the form of [products] / [reactants]. Starting with a balanced equation will help!
Ag2SO4(s) + H2O(l) <--> 2Ag+ (aq) + SO42-(aq)
So, the balanced equation tells us that Ksp = [Ag+]2[SO42-] . Note that pure solids and pure liquids never appear in the equilibrium constant expression.
Since you're starting with 0.0155 M Ag2SO4(s), the coefficients from the balanced equation tells us that you're producing 2(0.0155 M) Ag+(aq) and 1(0.0155 M) SO42-(aq). We can plug those values in to get Ksp.
Ksp = [Ag+]2[SO42-] = (0.031 M)2(0.0155 M) = 1.49 X 10-5
If you were to use an ICE table to solve this problem, you should arrive at the same result.
