Apparent Equilibrium Constants 239 18873.6 ) / loPMg 10 6 1.9699 10 + 2.91545 10 ((1 + + lo2 pH 1 OPH 8 -pH - pMg 293789. 8196.72 2.47072 10 10 +- +- ) LW[lOl) 102 PMg 10PMg