Exploring Thermodynamics Using Non-traditional Systems: Elastomers and DNA©
Jeffrey A. Draves
Monmouth College
Department of Chemistry
700 E. Broadway
Monmouth, Il 61462
United States
mail to: jeffd@monm.edu

Traditional undergraduate physical chemistry courses focus much of their efforts on matter in the gas phase. While a useful approach, the scarcity of applications of the first and second laws of thermodynamics to solids and liquids can leave students with the impression that thermodynamics is only applicable to substances in the gas phase. In this worksheet thermodynamic analysis is applied to elastomers. We begin with the concept of an equation of state and work through several examples analogous to the ideal gas law. The approach used here follows closely the work of B. Smith 1,2 and J. E. Mark. 3 The analysis is extended to DNA stretching data to illustrate even wider applicability of thermodynamic concepts and tools. Mathcad is particularly useful for elastomer and DNA analysis. The worksheet can be used anytime after the First and Second Laws of Thermodynamics but does assume that the student has already seen application of these laws to gas phase systems. The worksheet relies on the use of data taken directly from the literature and requires the use of several Mathcad functions including, importing data, the coding environment, and symbolic mathematical operation.
Editor's Commentary
Audiences: Upper-Division Undergraduate
Pedagogies: Computer-Based Learning
Domains: Physical Chemistry
Topics: Biophysical Chemistry, Mathematics / Symbolic Mathematics, Nucleic Acids / DNA / RNA, Thermodynamics
File NameDescriptionSoftware TypeSoftware Version
data.zip JCE Archive of Data Files
Elastomerthermo11.mcd JCE Mathcad Computational Document Mathcad 11
Elastomerthermo11.pdf Read-Only Document
JCE JCE Subscribers only: name and password or institutional IP number access required.
1. Smith, B. "Using Rubber-Elastic Material - Ideal Gas Analogies To Teach Introductory Thermodynamics, Part I: Equations of State," J. Chem. Ed. 2002, 79, 1444-1452.
2. Smith, B. "Using Rubber-Elastic Material - Ideal Gas Analogies To Teach Introductory Thermodynamics, Part II: The Laws of Thermodynamics," J. Chem. Ed. 2002, 79, 1453-1461.
3. Mark, J. E. "Some Aspects of Rubberlike Elasticity Useful in Teaching Basic Concepts in Physical Chemistry," J. Chem. Ed. 2002, 79, 1437-1443.
Draves, J. A. J. Chem. Educ. 2007, 84, 1887
Comments to: Jeffrey A. Draves at jeffd@monm.edu
©Copyright 2007 Journal of Chemical Education