LIMITING PARTIAL MOLAR VOLUMES OF TETRA-N-ALKYLAMMONIUM BROMIDES IN XDIMETHYLFORMAMIDE-PLUS-(1-X)WATER MIXTURES AT 298.15-K

Partial molar volumes at infinite dilution, V-2(infinity), of tetra-n- alkylammonium bromides, R4NBr (R=methyl, ethyl, propyl, butyl, pentyl) , have been determined in binary mixtures of water with N,N-dimethylfo rmamide (DMF) over the entire composition range at 298.15 K. Variation s of V-2(infinity) with the mole fraction of DMF as a function of solv ent composition and electrolyte are considered. A linear dependence be tween V-2(infinity) of the electrolyte and the molecular weight of the tetraalkylammonium cation was found.