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+> + NO3<1-> = »Si-OH2-NO3 logK = 2.1(1.8) »Si-OH + H<1+> = »Si-OH2<1+> -pK1 = logK = -1.4 sum »Si-OH + NO3<1->+ H<1+> = »Si-OH2-NO3 logK = 2.1(1.8)-1.4 = 0.7(0.4)