Nitrate Selectivity of Ion-Exchange Resins and of Their Model Compounds. I. Conductance Measurements on Benzyltrialkylammonium Salts

Abstract

The concentration dependence of the conductance in aqueous solution of a series of benzyltrialkylammonium chlorides, nitrates and sulfates was measured. The n-alkyl substituents in this series were methyl, ethyl, propyl , butyl and pentyl. The conductances of the chlorides, nitrates and sulfates fit satisfactorily the electrostatic ion pairing models relevant to 1 : 1 and 1 : 2 electrolytes. The extent of ion pairing is small in all the solutions studied but consistently larger for nitrates and sulfates compared with chlorides. The dependence of the association constants on the alkyl substitutents shows different trends for the monovalent anions compared with the sulfate salts.