TY - JOUR

T1 - Modeling heat capacities of high valence-type electrolyte solutions with Pitzer's equations

AU - Criss, Cecil M.

AU - Millero, Frank J.

N1 - Funding Information:
We acknowledge the support of the Oceanographic Section of the National Science Foundation. The authors thank Professor Robert H. Wood for helpful discussions in the mathematical treatment of the data. This work is dedicated to the memory of Professor Kenneth S. Pitzer, whose pioneering work in this field made these calculations possible.

PY - 1999/7

Y1 - 1999/7

N2 - Apparent molar heat capacities Cp,Φ for 71 rare earth chlorides, nitrates, and perchlorates, alkaline earth and transition metal chlorides, nitrates, and perchlorates, and alkali metal carbonates and sulfates have been fitted to the Pitzer equation for heat capacities. The apparent molar heat capacities at infinite dilution Cop,Φ (equal to the standard partial molar heat capacity, Cop,2) were used to evaluate a set of "best" ionic heat capacities, from which improved values of Cop,Φ for the electrolytes were calculated. These were then used in the Pitzer equation to reevaluate the higher Pitzer coefficients. The Pitzer coefficients so evaluated can express, in most cases, the behavior of Cp,Φ within experimental error from infinite dilution to the upper limit of the data. Ionic heat capacities have been correlated with the absolute entropies of the ions by statistically assigning the ionic heat capacities to obtain the best linear fit.

AB - Apparent molar heat capacities Cp,Φ for 71 rare earth chlorides, nitrates, and perchlorates, alkaline earth and transition metal chlorides, nitrates, and perchlorates, and alkali metal carbonates and sulfates have been fitted to the Pitzer equation for heat capacities. The apparent molar heat capacities at infinite dilution Cop,Φ (equal to the standard partial molar heat capacity, Cop,2) were used to evaluate a set of "best" ionic heat capacities, from which improved values of Cop,Φ for the electrolytes were calculated. These were then used in the Pitzer equation to reevaluate the higher Pitzer coefficients. The Pitzer coefficients so evaluated can express, in most cases, the behavior of Cp,Φ within experimental error from infinite dilution to the upper limit of the data. Ionic heat capacities have been correlated with the absolute entropies of the ions by statistically assigning the ionic heat capacities to obtain the best linear fit.

KW - Alkali metal sulfates

KW - Apparent molar heat capacities

KW - Lanthanide elements

KW - Magnesium sulfate

KW - Partial molar heat capacities

KW - Pitzer's equations

KW - Transition metals

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U2 - 10.1023/A:1021732214671

DO - 10.1023/A:1021732214671

M3 - Article

AN - SCOPUS:0033242459

VL - 28

SP - 849

EP - 864

JO - Journal of Solution Chemistry

JF - Journal of Solution Chemistry

SN - 0095-9782

IS - 7

ER -