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-> + Na<1+> = »Si-O-Na logK = 1.4(0.9) »Si-OH = »Si-O<1-> + H<1+> pK2 = -logK = 7.0 sum »Si-OH + Na<1+> = »Si-O-Na + H<1+> logK= 1.4(0.9) -7 = -5.6(-6.1)