1. The problem statement, all variables and given/known data This is a derivation of the relation between solubility of a salt and pH of the solution in which it is dissolved from our textbook. Consider a salt MX whose Ksp=[M+][K-] If this were dissolved in a solution of the acid HX whose Ka=[H+][X-]/[HX] then what would be its solubility? Now Ka/[H+]=[X-]/[HX] or Ka/([H+]+ Ka)=[X-]/([HX]+[X-])=f say It can be seen that f decreases as pH decreases. If S were the solubility, Then Ksp=(S)(f*S) = S2(Ka+[H+])/Ka Could anyone please explain how Ksp=(S)(f*S) because I have no idea.