Effect of some protic and dipolar aprotic solvents on the H_ function in ethylene glycol

Abstract

The effect addition of some protic as well as some dipolar aprotic solvents to a 0.01M solution of sodium 2-hydroxyethoxide (NaO·C₂H₄·OH) in ethylene glycol on the H_ function of the system has been studied with some nitro-substituted amine indicators. The extent of enhancement of the (H_)^EG_Am function (i.e., the H_ function of the system measured with the amine indicators) is in the order Me₂SO > Me₂N·CHO > Bu^tOH > Me₂CO > MeCN > MeOH, whereas there is a small decrease in the function with the addition of water. The glycol–dimethylformamide–0.01M-NaO·C₂H₄·OH system has also been studied with some t-butylphenol indicators in order to investigate the role played by the changes in the activity coefficients of the neutral indicator acid (HA) and its anion (A^–) with changes in the solvent media in enhancing the H_ function of the system. Attempts have been made to understand the relative order of the different solvent in enhancing the (H_)^EG_Am function.