calculation from literature values with standard SSA and SSD at ionic strength of 1M, log K for Aerosil in brackets for Cabosil content »Si-O<1-> + K<1+> = »Si-O-K logK = 1.7(1.3) »Si-OH = »Si-O<1-> + H<1+> pK2 = -logK = 7.0 sum »Si-OH + K<1+> = »Si-O-K + H<1+> logK= 1.7(1.3) -7 = -5.3(-5.7)