Level: introductory (1-2), advanced (3-4)
Reference: James Prescott Joule, "Some Remarks on Heat and the Constitution of Elastic Fluids," Memoirs of the Manchester Literary and Philosophical Society November 1851 and Philosophical Magazine 14, 211ff (1857)
Notes: James Prescott Joule (1818-1889) was one of the key figures of 19th-century thermodynamics, best known for his experiments on the interconvertability of heat and mechanical energy. The SI unit of energy is the joule, named in his honor.
This paper is rather difficult for modern students to follow. Joule sometimes uses the term pressure where we would say force and weight in places where we would use mass. He is also rather less careful with units and significant figures than we would want our students to be.
Exercise 1 is a simple set of unit conversions that happens to use historical units. Exercise 2 is a matter of putting numbers into a formula from the kinetic theory of gases, combined with a bit of appreciation, I hope, for the fact that Joule obtained the same result 150 years ago. Both are suitable for introductory chemistry students.
Exercise 3 takes the student through a derivation somewhat akin to one found in most physical chemistry texts for the pressure of a gas according to the kinetic model. I find such derivations useful as examples of quantitative physical reasoning, and I suggest that exercise 3 can serve the same illustrative purpose. (What distinguishes Joule's derivation from modern textbook fare is Joule's aggregation of all the molecules of a gas into three lumps. This is not something a student would think of doing, and it offers an opportunity to pose the question of whether it is legitimate.) Exercise 3, then, is well suited for physical chemistry students studying the kinetic model of gases.
I would find it difficult to use exercise 4 in a chemistry class; perhaps an introductory physics class would be more appropriate for it. Exercise 4 is mainly a set of unit conversion problems, but one that requires physical concepts of force, pressure, mass, and weight. Exercise 4 would be very helpful for a modern reader of Joule's paper, but reading 19th-century scientific literature is not exactly a main learning objective of modern science courses!
Solutions: To download solutions, go to:
http://web.lemoyne.edu/giunta/classicalcs/joule.doc
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