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+> + ClO4<1-> = »Si-OH2-ClO4 logK = 1.7(1.5) »Si-OH + H<1+> = »Si-OH2<1+> -pK1 = logK = -1.4 sum »Si-OH + ClO4<1->+ H<1+> = »Si-OH2-ClO4 logK = 1.7(1.5)-1.4 = 0.3(0.1)