  In this work we propose a geometric view of the azeotropy problem, using some
simplified models. We demonstrate that the occurrence of azeotropes in binary
mixtures can be viewed-geometrically-as the intersection of curves in the plane
(for some models, these curves are parabolas). Furthermore, the idea of
functions from the plane to the plane is used to help understand the azeotropic
phenomenon. These ideas are illustrated with two simple cases, with one and two
azeotropes, allowing the analysis of a unusual thermodynamic behavior-such as
double azeotropy-with simple mathematical tools, by undergraduate students in
Chemical Engineering courses.
