Solubility
Solubility (S) = molar concentration of dissolved salt; ion concentrations are related to this by their coefficients.
AgCl: [Ag+] = S [Cl-] = S Ksp = (S)(S)
Ag2S: [Ag+] = 2S [S2-] = S Ksp = (2S)2(S)
Fe(OH)3: [Fe3+] = S [OH-] = 3S Ksp = (S)(3S)3