Question

Consider the reaction caso4(s)⇌ca2+(aq)+so2−4(aq) at 25 ∘c the equilibrium constant is kc=2.4×10−5 for this reaction.if excess caso4(s) is mixed with water at 25 ∘c to produce a saturated solution of caso4, what is the equilibrium concentration of ca2+?

Answer 1

According to the balanced equation of the reaction:
CaSO4(s) ↔ Ca2+(aq) + SO2-4(aq)
So Kc = [Ca2+] [SO2] and we have [Ca2+] & [SO2] are the same so we can assume it both by X
So KC = X^2
X^2 = 2.4 x 10^-5
X = √2.4X10^-5 = 0.004899 = 4.9 X 10^-3 m