Resumen

VASINI, E  y  DONATI, E. Thermodynamic concepts: Some consideration on their use in introductory courses of chemistry. An. Asoc. Quím. Argent. [online]. 2005, vol.93, n.1-3, pp.177-184. ISSN 0365-0375.

Most phenomena described in introductory university courses of chemistry have a solid thermodynamic conceptual foundation. It is unavoidable, at this initial level, to treat thermodynamic concepts partially (especially the second principle), and to use examples and applications corresponding to very definite and simple cases. In these conditions, great care must be exerted to help students avoid the misconceptions that they frequently adopt after being exposed to this partial vision of thermodynamics. The following are the most frequent ones: 1) to incorrectly extend to all isothermal processes in any system, the conclusion that the internal energy change is null for all isothermal expansion-compression processes of an ideal gas, 2) to unrestrictedly associate enthalpy changes with transferred thermal energy, 3) to unrestrictedly use free energy changes as spontaneity criteria. We discuss here how these false interpretations commonly develop, and propose possible alternatives to decrease their frequency.