Solubility with activity. Find the concentrations of the major species in a saturated aqueous solution of LiF. Consider the following reactions. LiF(S) = Li+ + F- Ksp = [Li+]yli+[F-]yf LiF(s) = LiF(aq) Kjon pair = [LiF(aq)]yLiF(aq) F- +1,0 = HF + OH- Kb = Kw/K (for HF) HP0 = H+ + OH- Kw = [H+1Y+[OHIYOH Look up the equilibrium constants and report their pK values. The ion pair reaction is the sum of Lif(s) = Lit + F- and Li+ +F = LiF(aq). рКр = pKjon pair pKb = pKw = Write the equilibrium constant expresions and the charge and mass balances. charge balance: mass balance:
Create a spreadsheet that uses activities to find the concentrations of all species and the ionic strength. Use pF- and po- as independent variables to estimate. It does not work to choose pF- and pLit because either concentration fixes that of the other through the relation Ksp = [Li+]yli+[F-lys- F-1 = M [OH-] = M [Li+] = M [LiF(aq)] = M [HF] = M [H+] = M H = M