A solution containing sulfide ions is added to selectively precipitate one of the metal ions from solution. At what concentration of sulfide ion will a precipitate begin to form? What is the identity of the precipitate? Ksp(CuS)= 1.4 x 10^-36, Ksp(FeS)= 6.3 x 10^-18. Explain the rationale for your answer.0^-36, Ksp(FeS)= 6.3 x 10^-18. Explain the rationale for your answer.