Acidity of hyperconcentrated electrolyte solutions. Hammett acidity function measurements for aqueous ZnCl₂, + LiCl solutions

Abstract

The Hammett acidity function has been evaluated by means of spectrophotometric measurements with thymol blue indicator for (1-x)(ZnCl₂,RH₂O)+x(LiCl,RH₂O) pseudobinary mixtures where R is 4 and 6. The pseudobinary mixtures have well defined minimum acidity near the composition (x = 0.67) which corresponds to the tetrachlorozincate ion stoichiometry. The acidity data for these mixtures support the conclusion that the properties of mixtures with R ≤ 6 are dominated by formation of tetrachlorozincate anions.