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CH1012
PREDICTING SOLN.
SPECIES.
• The formation constant Kf is used to predict which species are likely to be found in solution.
A large
Kf value indicates
that the complex will be present in excess over ions/ligands.
• The solubility
product KSP is used to predict if a compound will form as a solid given certain concentrations of the cation and ligands. It
is a general concept and applies
equally well to ionic compounds.
• eg. AgCl(s) D Ag+(aq) + Cl-(aq) KSP 1.6 x 10-10
if [Ag+] = 10-3 mol/dm3 & [Cl-] = 10-4 mol/dm3
then the product [Ag][Cl] = 10-7 , this clearly exceeds KSP and so AgCl will precipitate.
if [Ag+] = 10-3 mol/dm3 & [Cl-] = 10-4 mol/dm3
then the product [Ag][Cl] = 10-7 , this clearly exceeds KSP and so AgCl will precipitate.
