Apparent Molar Heat Capacities and Volumes of Mixed Electrolytes: [NaCl(aq) + CaCl2(aq)], [NaCl(aq) + MgCl2(aq)], and [CaCl2(aq) + MgCl2(aq)]

1995 ◽  
Vol 40 (2) ◽  
pp. 398-406 ◽  
Author(s):  
Preet P. S. Saluja ◽  
David J. Jobe ◽  
Jacques C. LeBlanc ◽  
Robert J. Lemire
Keyword(s):  
Heat Capacities ◽  
Mixed Electrolytes ◽  
Apparent Molar Heat Capacities

Thermodynamics of aqueous EDTA systems: Apparent and partial molar heat capacities and volumes of aqueous EDTA4−, HEDTA3−, H2EDTA2−, NaEDTA3−, and KEDTA3− at 25 °C. Relaxation effects in mixed aqueous electrolyte solutions and calculations of temperature dependent equilibrium constants

1988 ◽  
Vol 66 (4) ◽  
pp. 881-896 ◽  
Author(s):  
Jamey K. Hovey ◽  
Loren G. Hepler ◽  
Peter R. Tremaine
Keyword(s):  
Equilibrium Constants ◽  
Interaction Model ◽  
Electrolyte Solutions ◽  
Heat Capacities ◽  
Mixed Electrolytes ◽  
Temperature Dependent ◽  
Apparent Molar Heat Capacities ◽  
Partial Molar Heat Capacities ◽  
Relaxation Effects ◽  
Young's Rule

Calorimetric and densimetric measurements have led to apparent molar heat capacities and volumes for aqueous solutions of the mixed electrolytes [(CH3)4N]4EDTA + (CH3)4NOH, Na4EDTA + NaOH, and K4EDTA + KOH, and single electrolytes Na2H2EDTA and [(CH3)4N]3[HEDTA] at 25 °C. We have analyzed these results in terms of Young's rule and Pitzer's ion interaction model to obtain standard state partial molar heat capacities and volumes of EDTA4−(aq), HEDTA3−(aq), H2EDTA2−(aq), NaEDTA3−(aq), and KEDTA3−(aq) at 25 °C. For these calculations it was also necessary to evaluate the "relaxation" contribution to the measured heat capacities of some solutions. The partial molar heat capacities obtained here have been used with enthalpies from previous investigations for calculations of several equilibrium constants over wide ranges of temperature; volumes can be used for similar calculations of the effects of pressure.

Apparent molar heat capacities and volumes of aqueous electrolytes at 25°C: NaIO3, KMnO4, and MnCl2

1979 ◽  
Vol 28 (1) ◽  
pp. 155-160 ◽  
Author(s):  
Jan J. Spitzer ◽  
Inger V. Olofsson ◽  
Prem Paul Singh ◽  
Loren G. Hepler
Keyword(s):  
Heat Capacities ◽  
Aqueous Electrolytes ◽  
Apparent Molar Heat Capacities

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.

Apparent molar heat capacities and volumes for HClO4(aq) to 373 K

1996 ◽  
Vol 286 (2) ◽  
pp. 225-231 ◽  
Author(s):  
Robert J. Lemire ◽  
Allan B. Campbell ◽  
Pujing Pan
Keyword(s):  
Heat Capacities ◽  
Apparent Molar Heat Capacities
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