Liquid densities and excess molar volumes for (ionic liquids + methanol + water) ternary system at atmospheric pressure and at various temperatures

Abstract

Excess molar volumes, V m E have been evaluated from density measurements over the entire composition range for ternary liquid system of ionic liquid (1-ethyl-3-methyl-imidazolium diethylenglycol monomethylether sulphate {[EMIM][CH 3(OCH 2CH 2) 2OSO 3]) (1) + methanol (2) + water (3)} at T = (298.15, 303.15, and 313.15) K. A vibrating tube densimeter was used for these measurements at atmospheric pressure. The V m E values were found to be negative at T = (298.15 and 303.15) K. For {[EMIM][CH 3(OCH 2CH 2) 2OSO 3] (1) + methanol (2) + water (3)} at T = 313.15 K the V m E values become positive at higher mole fraction of ionic liquid and at a corresponding decrease in mole fraction of water. All the experimental data were fitted with the Redlich–Kister equation. The results have also been analysed in term of graph theoretical approach.