Un experimento para ilustrar el primer principio de la termodinámica en bachillerato: creación de una nube de alcohol dentro de una botella

Abstract

This article proposes to conduct a simple experiment as a didactic resource for the study of the first law of thermodynamics in high school, although it can also be used in other contexts and at different educational levels. Taking into account the students to whom this proposal is intended, an essentially qualitative analysis of the physical processes involved in this experiment (evaporation-condensation of a liquid and compression-expansion of a gas) is carried out. In addition, the possible use of other liquids (especially, water) to carry out the experiment is discussed and several complementary experiments are proposed that help to understand why the cloud is formed.