Conceptual and epistemological difficulties of future teachers of physics and chemistry in the energetic explanations of physical and chemical phenomena

In this paper we analyze the conceptual and epistemological difficulties which have on thermochemical the physics, chemistry and chemical engineering students that they are preparing to be teachers of physics and chemistry. It has been applied to a sample of 35 prospective teachers’ two questionnaires on thermal effects in physical and chemical phenomena that explain them and we have categorized their responses according to the reasoning used. It has been confirmed that most of the students do not know delimit systems that interact, do not use the concept of internal energy and the first law of thermodynamics in physical processes. Almost none trainee teachers use submicroscopic reasoning to explain these thermal effects in the physical and chemical changes and almost every explanations are incorrect.