Constructing the Phase Diagram of a Single-Component System Using Fundamental Principles of Thermodynamics and Statistical Mechanics: A Spreadsheet-Based Learning Experience for Students

Abstract

A spreadsheet project that enables students to construct chemical potential vs temperature plots, μ(T), of liquid and gaseous mercury and all three phases of diiodine and ammonia is presented. Statistical thermodynamics is used to determine the entropies of the substances in the gas phase. For the solid and liquid phases, students start with published heat capacities, third law entropies, and other thermodynamic quantities to obtain entropies over the range of temperatures needed. By using thermodynamic cycles, they calculate the chemical potentials of the metastable phases at standard conditions. With these values as starting points, students use the Gibbs equation and stepwise integration to obtain the chemical potentials over a range of temperatures. Using this data, they calculate the melting and boiling points and transition enthalpies and entropies from the intersection points of the two phases. The calculated thermochemical quantities are in excellent agreement with literature values.

Using the Principles of Classical and Statistical Thermodynamics To Calculate the Melting and Boiling Points, Enthalpies and Entropies of Fusion and Vaporization of Water, and the Freezing Point Depression and Boiling Point Elevation of Ideal and Nonideal Aqueous Solutions

“…1 In the preceding article, we presented the methods and tools that enable students to calculate the chemical potential, μ, of the solid, liquid, and gas phases of mercury, diiodine, and ammonia (at 1 bar) as a function of temperature. 2 Students used these results to construct graphs of μ vs T and to calculate the intersection point of the μ gas (T) and μ liq (T) curves, enabling them to obtain the standard boiling point T sbp . From this information, they also calculated the molar enthalpy and entropy of vaporization, Δ vap H m and Δ vap S m .…”

Teaching Thermodynamics with the Quantum Volume

“…Some are pictorial analogies intended for beginner students. , Others are appropriate for intermediate students who have completed their first year of freshmen science . The intermediate pictorial concepts range from probability, gas kinetics, and spreadsheets , to new diagrams . Lastly, there are advanced pictorial methods to visualize entropy intended for graduate students.…”