Phase equilibria, volumetric and compressibility properties of (tetra-n-butylammonium bromide + trisodium citrate) system at temperatures (298.15 K–318.15 K) and atmospheric pressure

Liquid−liquid equilibrium data and phase diagram corresponding to new (salt + salt) aqueous biphasic system composed of tetra-n-butylammonium bromide and trisodium citrate were determined by varying temperature and atmospheric pressure. The effects of temperature and salt induced on the binodals and tie-lines of the investigated ATPS were also studied. It was found that an increase in temperature caused the expansion of the two-phase region and increased the slope and the length of the tie line. In order to obtain further evidence about the salting-out effect produced by the addition of trisodium citrate, Na3Cit to an aqueous solution of water-miscible tetra-n-butylammonium bromide, volumetric and compressibility behavior have been measured at temperatures (298.15 K–318.15 K). The densities and speeds of sound data have been utilized to calculate apparent molar volumes, Vϕ, the apparent molar isentropic compressibility, κϕ, the values of the apparent molar quantity at infinite dilution, Vϕο, κϕο and partial molar characteristics include the volume and compressibility of transfer at infinite dilution, ΔtYϕο, TBAB from pure water to the aqueous salt solution.