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The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 3 Issue 2 (1998), S1430-4171(98)02201-5

Use of the Murnaghan-Hildebrand Equation of State in Teaching Thermodynamics

Reed A. Howald

Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717

Published online: 2 April 1998

Abstract. The Murnaghan-Hildebrand equation of state, an accurate equation of state for many solids and liquids, is introduced for use in the illustration of thermodynamic relationships. It is shown to meet the need for an equation of state accurate over a wide range of pressures. Parameters are given for four solid phases of iron and for the liquid, with which eleven thermodynamic functions including V, U, H, S, aV, V/B, and G can be calculated at any specified temperature and pressure. The program for these calculations can be used to represent experimental values, to illustrate thermodynamic relationships, to calculate chemical and phase equilibria, and to stimulate student interest from the study of real systems, for instance, the form of iron in the core of the earth.

Key Words:  In the Classroom; thermodynamics; Murnaghan-Hildebrand; physical chemistry

(*) Corresponding author. (E-mail: howald@montana.edu )

Article in PDF format (121 KB )

Supporting Materials:

The computer format used by The Chemical Educator allows one to keep the main body of a paper short, but provide additional material in a variety of formats for anyone who wishes to pursue some particular point further. The main part of the paper in the file FE20.TXI includes 6 tables and 1 figure. Each of these is available as a separate file of supporting material as shown below. The paper describes the computer program PHF, copyrighted by Montana Interface Incorporated, P. O. Box 6567, Bozeman, MT 59771. A subscription to The Chemical Educator entitles you to up to three copies of this program, so it and 11 supporting files for its use are included in the supporting material in 32rh2897.zip. In addition there are answers to five questions: 1.) Why do students need practice with equations like the maxwell equations? in SUPP20.TXI in 2rh1897.zip. 2.) What about equations of state for gases? in SUPP21.TXI in 32rh1897.zip. 3.) How accurately do the calculations for Figure 1 represent the experimental data on iron at high pressures? in IRON5.TXH in 32rh2897.zip with figures and tables as listed in SUPPPORT.TXI in 32rh1897.zip. 4.) What problems can one use for homework and examinations on the temperature and pressure dependence of thermodynamic variables? in SUPP23.TXI in 32rh1897.zip. 5.) How can one improve the modelling for a particular material like hexagonal iron? in SUPP24.TXI in 32rh1897.zip.

Associated document (32rh1897.zip, 18 KB)10.1007/s00897980201b

Associated document (32rh2897.zip, 242 KB) 10.1007/s00897980201c


Issue date: April 2, 1998

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