Given Ksp, how can I calculate solubility?

I'm told the Ksp of #CdF_2# is #6.44\times10^-3# and asked to determine the solubility. How would I go about doing this?

Thanks!

1 Answer
Mar 10, 2018

#K_"sp"# is a quantitative measure of a solid's solubility in solution.

Consider,

#CdF_2(s) rightleftharpoons Cd^(2+)(aq) + 2F^(-)(aq)#

where, #K_"sp" = [Cd^(2+)][F^-]^2 = 6.44*10^-3#

Moreover, consider that for every portion of cadmium ions that dissolve, two portions of fluoride ions will dissolve, such that at equilibrium,

#K_"sp" = x * (2x)^2 = 6.44*10^-3#

Hence,

#therefore x approx 0.117M#

is the approximate solubility of cadmium (II) fluoride give your data.