Comment: A problem in extracting structure information from the temperature of maximum density for aqueous solutions

1977 ◽  
Vol 55 (5) ◽  
pp. 798-799 ◽  
Author(s):  
James R. Kuppers
Keyword(s):  
Aqueous Solutions ◽  
Solution Structure ◽  
Maximum Density ◽  
Reference State ◽  
Temperature Dependent ◽  
Structure Information ◽  
Ideal State ◽  
Structural Contribution ◽  
Temperature Of Maximum Density ◽  
Temperature Dependent Properties

The shift in the temperature of maximum density for aqueous solutions customarily has been dissected into an ideal and a structural contribution. This analysis demonstrates that the dissection leads to the formulation of an ideal state which is attained by a fortuitous superposition of temperature dependent properties of pure components and, hence, cannot serve as a reliable reference state for comparing the influence of different solutes upon solution structure.

Reply to comment: "A problem in extracting structure information from the temperature of maximum density for aqueous solutions"

1977 ◽  
Vol 55 (5) ◽  
pp. 800-801 ◽  
Author(s):  
Digby D. MacDonald
Keyword(s):  
Aqueous Solutions ◽  
Structural Information ◽  
Preceding Paper ◽  
Maximum Density ◽  
Proper Choice ◽  
Standard State ◽  
Structure Information ◽  
Structure Of Water ◽  
Temperature Of Maximum Density

The arguments presented by Kuppers in the preceding paper on the use of the temperature of maximum density parameters Δθ and Δθst for the analysis of the effect of solutes on the structure of water are critically examined. The validity of these arguments is challenged on both theoretical and experimental grounds. In particular, the proper choice of the standard state is stressed, and it is demonstrated that Δθst contains structural information which cannot be extracted from Δθ directly.

Temperature of Maximum Density for Binary Aqueous Solutions of Five Amino Acids

2019 ◽  
Vol 64 (12) ◽  
pp. 5847-5856 ◽  
Author(s):  
Jacobo Troncoso ◽  
Diego González-Salgado ◽  
Luis Romaní
Keyword(s):  
Amino Acids ◽  
Aqueous Solutions ◽  
Maximum Density ◽  
Temperature Of Maximum Density

Excess volumes for ethanol + water mixtures at 10-K intervals from 278.15 to 338.15 K

1980 ◽  
Vol 33 (10) ◽  
pp. 2121 ◽  
Author(s):  
KN Marsh ◽  
AE Richards
Keyword(s):  
Infinite Dilution ◽  
Excess Volume ◽  
Composition Range ◽  
Maximum Density ◽  
Excess Volumes ◽  
Temperature Dependent ◽  
Molar Excess ◽  
A Value ◽  
Molar Excess Volume ◽  
Temperature Of Maximum Density

The excess volumes of mixtures of xA ethanol+ xB water have been measured at 10-K intervals from 278.15 to 338.15 K over the whole composition range, various dilution dilatometers being used. Particular attention has been paid to regions dilute in both ethanol and water. The partial molar excess volume of ethanol at infinite dilution in water is extremely temperature-dependent, becoming more negative as the temperature increases. The partial molar excess volume of ethanol in dilute solutions is very concentration-dependent at low temperatures but the dependence approaches zero at 362 K. At an xA value of 0.038, the partial molar excess volume of ethanol VEA is independent of temperature, having a value of -5.23 cm3 mol-1, while the excess volume VEA is independent of temperature at xA = 0.082, having a value of -0.420 cm3 mol-1. These unusual observations are explained in terms of the variation of the temperature of maximum density with composition for dilute ethanol solutions. At high mole fractions of ethanol the excess volume and the partial molar excess volume of water do not show unusual behaviour.

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