(676e) Degrees of Freedom - Not Just for Sophomores

Typically, chemical engineering students are introduced to the concept of degrees of freedom along with mass balances where the concept is used to help formulate balances and related equations and again in thermodynamics in the context of phase equilibrium.  Unfortunately, the concept is not used beyond these contexts, the formalisms are not directly derivable one from the other and, as a consequence students do not ascertain that the concept is more generalizable than these specific applications would lead them to believe.  Since, the degrees of freedom concept is generally not practiced outside of these isolated contexts and, in fact, in subsequent courses, students that learned these formalisms will revert to “hunt and peck” strategies for solving material balances and for doing thermodynamic phase or reaction equilibrium calculations; rather than apply a degrees of freedom analysis as a starting point.  This lack of skill and understanding limits the students’ ability to accurately formulate problems; an area that can be greatly improved by implementing a pervasive approach to the utilization of a robust and generalized degrees of freedom formalism throughout the curriculum.  Therefore, an extended degrees of freedom formalism is proposed that can be applied to steady and dynamic processes.  The new formalism is an extension of existing practices that in general do not collapse to the Gibbs Phase Rule and do not work for dynamic situations.