A solution is prepared by adding some solid BaF2 to water and allowing the solid to come to equilibrium with the solution. The equilibrium constant for the reaction below is Kc = 1.3x10-6.
BaF2(s) → Ba2+(aq) + 2 F -(aq)
What is the equilibrium concentration of Ba2+ in the solution? Assume that some of the solid remains undissolved.
Give your answer in moles per litre, accurate to two significant figures. Do not include units as part of your answer. (Enter 1.23x10-5 as 1.23e-5.)