Measurement and modeling of mean activity coefficients of NaBr and amino acid in (sodium bromide+potassium phosphate+glycine+water) system at T (298.15 and 308.15)K

Measurement and modelling of mean activity coefficients of aqueous mixed electrolyte solution containing glycine

“…On the other hand, an increase in glycine molality at constant molality of NaBr and K 3 PO 4 causes a decrease in the ratio ðc III AE =c I AE Þ. This behaviour has been observed by previous workers [1,[9][10][11] and has been interpreted by ion-ion interactions between K + and Na + and the ion-dipole interactions between glycine and ions present in the solution due to the large dipole moment of glycine [12,19]. However, the presence of K + and PO 3À 4 causes some of the glycine molecules to form ion pairs with these ions and thereby increases the activity coefficient ratio of NaBr (see figure 2).…”

“…The modification of the Pitzer equation correlated the experimental data obtained in this study as was seen in previous work [1]. It is worth mentioning that the modified equation used in our study has only four adjustable parameters and can fit the experimental result over a different range of NaBr, K 3 PO 4 and glycine molalities.…”

“…Our group recently reported data for activity coefficients of glycine in mixed electrolyte solution containing NaBr and K 3 PO 4 at constant molality of K 3 PO 4 and different molalities of NaBr and glycine [1]. As the molality of K 3 PO 4 was kept constant, the effect of variation of K 3 PO 4 molality on activity coefficients of NaBr and glycine was not investigated.…”

The effect of ammonium sulfate on the solubility of amino acids in water at (298.15 and 323.15)K

“…Many of them are related to volumetric and viscometric properties [1][2][3][4][5][6][7], or activity coefficients measurements [8][9][10][11] to name some of them, but a very few were carried out on solubility [12][13][14] or water activity data [15], all almost exclusively at 298.15 K. In fact, the knowledge of properties such as activity coefficients, water activity, and solubility are very useful as a support for the efficient design and simulation of separation processes such as extraction, precipitation, or drying [10,16]. On the other hand, amino acids have been used extensively as model compounds for more complex molecules such as proteins, but a more profound understanding of the electrolyte effect on amino acid solutions is still needed to reveal the molecular interactions between salts and protein functional groups [6].…”

Mean ionic activity coefficient ratio of NaBr and DL-valine in the (water+DL-valine+NaBr+K3PO4) system at T=(298.2 and 303.2)K

“…In all experiments, the potentials of a sodium-ion selective electrode against bromide-ion 298.15K were used from [38] because chirality has no effect in physical and chemical properties the solutions [42], that is, the two enantiomers of Valine (D and L) have the same effect in studied system. The experimental results for each system are presented in tables 2, 3 and 4.…”