RESUMO
This study describes the application and evaluation of a novel didactic tool (thermodynamic device) developed for students in the area of biology who have conceptual deficiencies that render the learning of thermodynamic principles difficult. Systems of communicant vessels with equal and different compartments were constructed to correlate the equilibrium constant of the reactions and reagent/product ratios with the concept of standard and nonstandard Gibbs free energy changes (ΔG° and ΔG, respectively). The communicating vessels were filled respectively with equal and different volumes of a dye aqueous solution followed by the opening of a faucet that coupled the vessels. This procedure allows liquid flux leading to the movement of internal propellers. The movement of the propellers turns on an electronic circuit that processes the information to exhibit the energy released by the movement of the solution toward equilibrium. The thermodynamic device was evaluated regarding the efficiency of content comprehension and retention of the gain by challenging students to answer five subjective questions 1 week after a regular teaching module about thermodynamics. The overall mean score obtained by the students who accessed the thermodynamic device (7.0) was significantly higher (p < 0.01) than the mean score of the control group (3.4). The thermodynamic device increased twofold the percentage of students who gave more than 50% correct answers. The efficiency of the didactic tool was also evaluated and corroborated by objective questions. In conclusion, the use of the thermodynamic device was highly effective in improving the understanding of thermodynamic principles by undergraduate biology students.
