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Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1995 Jun 6;92(12):5597–5599. doi: 10.1073/pnas.92.12.5597

Significant discrepancies between van't Hoff and calorimetric enthalpies.

H Naghibi 1, A Tamura 1, J M Sturtevant 1
PMCID: PMC41743  PMID: 7777555

Abstract

In this paper we show that the usual assumption in studies of the temperature variation of equilibrium constants for equilibria of the form A+B <-->AB that a plot of ln K vs. 1/T (K = equilibrium constant, T = temperature in degrees kelvin) is a straight line with slope equal to -delta HvH/R (delta HvH = van't Hoff or apparent enthalpy, R = gas constant) is not valid in many cases. In all the cases considered here, delta HvH is temperature dependent and is significantly different from the true or calorimetrically measured enthalpy, and the respective values for delta Cp are also significantly different.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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