Temperature dependence of apparent molar volumes and viscosity B-coefficients of amino acids in aqueous potassium thiocyanate solutions from 15 to 35�C

1992 ◽  
Vol 21 (2) ◽  
pp. 163-170 ◽  
Author(s):  
Ramesh K. Wadi ◽  
Rma Kant Goyal
Keyword(s):  
Amino Acids ◽  
Temperature Dependence ◽  
Potassium Thiocyanate ◽  
Apparent Molar Volumes ◽  
Molar Volumes ◽  
B Coefficients

scholarly journals Volumetric, viscometric and refractive index behavior of amino acids in aqueous glycerol at different temperatures

2007 ◽  
Vol 72 (5) ◽  
pp. 495-512 ◽  
Author(s):  
A. Ali ◽  
S. Khan ◽  
F. Nabi
Keyword(s):  
Amino Acids ◽  
Mixed Solvents ◽  
Partial Molar Volumes ◽  
State Theory ◽  
Apparent Molar Volumes ◽  
Ternary Mixtures ◽  
Refractive Indices ◽  
Glycerol Solution ◽  
Molar Volumes ◽  
B Coefficients

Densities, ?, viscosities, ? and refractive indices, n D, of solutions of some amino acids (glycine, DL-alanine, DL-? -amino- n-butyric acid, L-valine and L-leucine) in the concentration range 0.02 to 0.10 m in 5 % (v/v) aqueous glycerol were determined at 298.15, 303.15, 308.15 and 313.15 K. These experimental data were used to calculate the apparent molar volumes, ? v, the infinite dilution apparent molar volumes, ? v 0, the partial molar volumes of transfer, ? v 0 (tr), of the amino acids from aqueous to aqueous glycerol solution, as well as the viscosity A and B coefficients of the Jones-Dole equation of the amino acids. The free energies of activation of viscous flow, ??1 0# and ?? 2 0# per mole of solvent and solute, respectively, were obtained by application of the transition-state theory to the B coefficient data and the corresponding activation enthalpy, ?H*, and entropy, ?S*, were also determined. The ? v 0, B coefficients and ?? 2 0# were found to vary linearly with increasing number of carbon atoms in the alkyl chain of the amino acids, and they were split into contributions from the zwitterionic end groups (NH3 +, COO-) and methylene (CH2) groups of the amino acids. The experimental values of the refractive indices, n D, were used to calculate the molar refractive indices, R D, of the amino acids + aqueous glycerol ternary mixtures. The results were interpreted in the light of the solute-solvent and solute-solute interactions in the mixed solvents.

Apparent molar volumes and viscosity B-coefficients of some α-amino acids in aqueous solutions from 278.15 to 308.15K

1999 ◽  
Vol 334 (1-2) ◽  
pp. 17-27 ◽  
Author(s):  
Zhenning Yan ◽  
Jianji Wang ◽  
Wenbin Liu ◽  
Jinsuo Lu
Keyword(s):  
Amino Acids ◽  
Aqueous Solutions ◽  
Apparent Molar Volumes ◽  
Molar Volumes ◽  
B Coefficients

Apparent molar heat capacities and volumes of some aqueous solutions of aliphatic amino acids at 288.15, 298.15, 313.15, and 328.15 K

1994 ◽  
Vol 72 (2) ◽  
pp. 362-368 ◽  
Author(s):  
Andrew W. Hakin ◽  
Michelle M. Duke ◽  
Sheri A. Klassen ◽  
Robert M. McKay ◽  
Kathryn E. Preuss
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aqueous Solutions ◽  
Equilibrium Constants ◽  
Heat Capacities ◽  
Apparent Molar Volumes ◽  
Protein Chemistry ◽  
Standard State ◽  
Apparent Molar Heat Capacities ◽  
Molar Volumes

The thermodynamics of amino acid systems are key to the understanding of protein chemistry. We have found that many previous studies of the apparent molar volumes and heat capacities of aqueous solutions of amino acids were conducted at the standard temperature of 298.15 K. This does not allow for the fact that most biological processes occur at temperatures removed from this standard condition.In an attempt to address this imbalance we have measured densities and heat capacities for aqueous solutions of glycine, L-alanine, L-serine, and L-threonine at 288.15, 298.15, 313.15, and 328.15 K using a Picker flow microcalorimeter. Apparent molar volumes and heat capacities, and the associated standard state partial molar properties have been calculated. Constant pressure variations of revised Helgeson, Kirkham, and Flowers equations have been fitted to calculated standard state volumes and heat capacities over the temperature range 288.15 to 328.15 K. These equations may be used to estimate standard state volumes and heat capacities, and hence equilibrium constants, for aqueous amino acid systems at higher temperatures.

Standard Volumes of Transfer for Some α-Amino Acids from Water to Aqueous Sodium Acetate Solutions at 298.15 K

2000 ◽  
Vol 214 (3) ◽  
Author(s):  
Jianji Wang ◽  
Z. Yan ◽  
Kelei Zhuo ◽  
D. Liu
Keyword(s):  
Amino Acids ◽  
Sodium Acetate ◽  
Apparent Molar Volumes ◽  
Molar Volumes ◽  
Aqueous Sodium

Apparent molar volumes, V

Viscosities of glycine and DL–alanine in water acetonitrile mixtures between 25 and 40 °C

1980 ◽  
Vol 58 (15) ◽  
pp. 1512-1515 ◽  
Author(s):  
Nibaran C. Dey ◽  
Birendra K. Saikia ◽  
Inamul Haque
Keyword(s):  
Apparent Molar Volumes ◽  
Molar Volumes ◽  
Increase With Increase ◽  
B Coefficients ◽  
Limiting Value

The relative viscosities and densities of glycine in 5%, 10%, 15%, and 20% w/w acetonitrile–water mixtures at 25, 30, 35, and 40 °C and of DL-alanine in water, 5%, 15%, and 20% w/w acetonitrile water mixtures at 30 and 40 °C have been determined. The viscosity B coefficients have been found to increase with increase in concentration of acetonitrile and also with the increase of temperature in both cases.The limiting apparent molar volumes and limiting value of effective flow volumes have also been calculated.

Excess enthalpies and apparent molar volumes of some N-methyl substituted amino acids in aqueous solutions

1989 ◽  
Vol 18 (2) ◽  
pp. 131-142 ◽  
Author(s):  
J. F. Reading ◽  
P. A. Carlisle ◽  
G. R. Hedwig ◽  
I. D. Watson
Keyword(s):  
Amino Acids ◽  
Aqueous Solutions ◽  
Apparent Molar Volumes ◽  
Excess Enthalpies ◽  
Molar Volumes

Apparent molar volumes of glycine, L-alanine, and L-serine in water + ethanol mixtures at 298.15 K

1999 ◽  
Vol 77 (3) ◽  
pp. 387-390 ◽  
Author(s):  
Xiaoling Ren ◽  
Ruisen Lin ◽  
Yaming Ni ◽  
Hanxing Zong
Keyword(s):  
Amino Acids ◽  
Hydrophobic Interactions ◽  
Pure Water ◽  
Apparent Molar Volumes ◽  
Molar Volumes ◽  
Transfer Volumes ◽  
Structure Breaking

Densities of glycine, L-alanine, and L-serine have been measured with an oscillating-tube densimeter at 298.15 K in water + ethanol (EtOH) mixtures ranging from pure water to 45% ethanol by mass. From these densities, apparent molar volumes and limiting apparent molar volumes of the three amino acids in the mixtures have been calculated. Transfer volumes are interpreted in terms of the structure-making or structure-breaking effects of water on addition of these amino acids in the mixtures. The relative contributions of hydrophilic and hydrophobic interactions in these solutions have been inferred.Key words: glycine, L-alanine, L-serine, water + ethanol mixtures, densities.

Apparent Molar Volumes and Viscosities of Some α-Amino Acids in Aqueous Sodium Butyrate Solutions at 298.15 K

2001 ◽  
Vol 46 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Zhenning Yan ◽  
Jianji Wang ◽  
Jinsuo Lu
Keyword(s):  
Amino Acids ◽  
Sodium Butyrate ◽  
Apparent Molar Volumes ◽  
Molar Volumes ◽  
Aqueous Sodium
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