New tools for teaching chemical engineering thermodynamics

The teaching toolbox described by Elliott and Lira (2000) has been expanded to include three new tools: molecular simulation, ConcepTesting, and a simplified version of the MOSCED model. The previous list of tools included: detailed derivations (e.g. Maxwell's relations), computational tools (calculator and xls), projects, homework, analogies, examples, tours, tests (including samples from past years), quizzes, and help sessions. Students were surveyed to rank these tools from "most instructive" to "least." The new tools are described briefly and the survey assessments are presented. The molecular simulation tool focuses on applets posted at: http://rheneas.eng.buffalo.edu/wiki/DMD. These applets provide visualization of molecular dynamics for ideal gases, hard spheres, and square-well spheres. The students are guided through several homework assignments in which they learn about temperature, energy, pressure, and system size. Further details are available online, so the remainder of this abstract focuses on the Simplified Separation of Cohesive Energy Density (SSCED). In the current work, the acidity and basicity parameters are adopted directly from the latest literature, but the polarity and dispersion parameters are lumped together and the total of all contributions is constrained to match the original Scatchard-Hildebrand solubility parameter. Three composition-dependent parameters of the MOSCED model are set to constants. In this way, the contrast between the physical interactions and the chemical interactions is more readily apparent and the model can be applied directly at all compositions in a self-consistent manner. Examples are given of in-class and exam assessments, along with homework assignments. The simplified model is intended to make the key concepts of hydrogen bonding accessible to any college student, including freshmen. ConcepTesting is demonstrated with in-class assessments of the SSCED model. ConcepTesting refers to an interactive form of class engagement especially as it applies to the use of student response "clickers. Students are prompted with multiple choice questions and their responses are instantly collected and displayed electronically. Students are encouraged to work in small groups (∼3) in developing their responses. A strict interpretation of ConcepTesting would limit questions to abstract conceptual content. In our implementation, we integrate conceptual content with more conventional examples and problem solving. This leads to a class that is continuously engaged.