Dependence of the density of solutions of alkali metal halides on the composition of methylpyrrolidone-water mixed solvents

The densities of solutions of alkali metal halides in methylpyrrolidone (MP)-water mixtures were measured at 298.15 K over the entire range of mixed solvent compositions. The standard partial molar volumes of the electrolytes (V) over bar degrees(2) were calculated. The (V) over bar degrees(2) values of alkali metal halides in MP-H2O mixtures were related linearly to the (V) over bar degrees(2) values in aqueous solutions. These dependences were used to determine the standard partial molar volumes of ions (V) over bar degrees(i) in the mixtures studied. The standard partial molar volumes of transfer of the ions from water into MP-water mixtures were calculated.