Partial molal heat capacities of tetraalkylammonium bromides in methanol from 10 to 50°C

Abstract

Enthalpies of solution habe beenmeasured for tetraethyl-, tetra-n-propyl-, and tetra-n-butylammonium bromides in anhydrous methanol at several temperatures ranging from 5 to 55°C. The data were extrapolated to infinite dilution by an extended Debye-Huckel equation to obtain standard enthalpies of solution ΔH30, and the integral heat method was employed to obtain partial molal heat capacities \(\overline C ^\circ _{p_2 } \), of the corresponding salts from 10 to 50°C. These data, along with similar data for tetramethylammonium bromide previously reported, were used to assign an, absolute heat capacity to the bromide ion in anhydrous methanol. Comparison of the absolute heat capacities of the bromide and tetraalkylammonium ions in water and methanol suggests that the processes occurring in the two solvents are quite dissimilar.