A General Chemistry Framework for Making Sense of the Chemical Potential, Work and Spontaneity in Chemical Reactions

While the concept of work is seemingly straightforward, owing to its microscopic nature, the work done during a chemical reaction, which we term chemical work is not immediately apparent to General Chemistry students, limiting their understanding of chemical thermodynamics. The framework proposed in this paper utilizes the physical picture of molecular mechanics to aid General Chemistry students in conceiving the microscopic interactions that contribute to chemical work during a reaction and promotes a physical - albeit qualitative - understanding of the elusive chemical potential, without the need for multivariate calculus. A simple proof-of-concept of the framework - the chemical reaction of the formation of gaseous hydrogen chloride - that serves as an in-class example is also presented in the paper. The example serves to reinforce the insights gleaned from the molecular mechanics picture, aid General Chemistry students in making connections to preexisting knowledge of chemical equilibria, and presents a more general definition of spontaneity of a chemical reaction in terms of the chemical potential.