calculation from literature values with standard SSA and SSD at ionic strength of 1M, log K for Aerosil in brackets for Cabosil content »Si-OH2<1+> + Cl<1-> = »Si-OH2-Cl logK = 1.4(1.0) »Si-OH + H<1+> = »Si-OH2<1+> - pK1 = logK = -1.4 sum »Si-OH + Cl<1->+ H<1+> = »Si-OH2-Cl logK= 1.4(1.0)-1.4 = 0(-0.4)