The activity coefficients of glycine, DL-Serine and DL-Valine in aqueous solutions containing nitrates at 298.15 K
โ Scribed by Chongxia Gao; Juan H. Vera
- Publisher
- John Wiley and Sons
- Year
- 2001
- Tongue
- English
- Weight
- 819 KB
- Volume
- 79
- Category
- Article
- ISSN
- 0008-4034
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โฆ Synopsis
Abstract
An electrochemical method was used to measure the mean activity coefficients of amino acids in waterโelectrolyteโamino acid systems. The amino acids were glycine, DLโserine and DLโvaline and the electrolytes were KNO~3~ and NaNO~3~. The activity coefficients of the electrolytes were obtained from the e.m.f measurements in an electrochemical cell with an anion and a cation ionโselective electrodes, each measured versus a double junction reference electrode at 298.15 K. The activity coefficients of the amino acids in the ternary systems were obtained from those of the electrolyte according to the cross differential relation. A simple semiโempirical model based on a modification of a more complex form, derived from perturbation theory, was used to correlate the activity coefficients in binary aqueous solutions and in ternary systems.
๐ SIMILAR VOLUMES
The activity coefficient data were reported for (water + potassium chloride + DL-valine) at T = 298.15 K and (water + sodium chloride + L-valine) at T = 308.15 K. The measurements were performed in an electrochemical cell using ion-selective electrodes. The maximum concentrations of the electrolytes
The partial molar isentropic pressure coefficients at infinite dilution k a S, 2 =-(1V a 2 /1p)S , where V a 2 is the partial molar volume at infinite dilution, have been determined for six N-acetyl amino acid and peptide amides in aqueous solution at the temperature 298.15 K. The results obtained h
Vapour-pressure lowerings of HO2CCH2C(OH)(CO2H)CH2CO2H(aq) (citric acid) solutions in the (0.51 to 7.65) molโขkg -1 molality range and at five temperatures from 298.15 K to 318.15 K were determined by applying the isoteniscopic technique. From these results, the apparent osmotic coefficients of HO2CC