text: the free energy change:\n\nchange(G') = - RT In K\n\n\n           = -(8.314J/K)(298K)In 8*10^-28\n       \n\n           = 154583J\n          \n           =  155 KJ\n\nThe molar solubility is the of moles of solute in 1 liter of a saturated solution(mol/L):\n\n\nksp =(Cd2+)(S2-)= 8*10^-28\n\n= X^2=8*10^-28\n\n X=  2.8*10^-14M\n\nM=mol/L\n\n\nsolve for mol:\n\n mol= M*L\n\n    = 2.8*10^-14mol/L*L\n    \n = 2.8*10^-14mol\n\n\nso the  free dissolution  energy is:\n\n2.8*10^-14mol CdS(155kJ / 1mol CdS) =4.34*10-12kJ