A new multimedia application for teaching and learning chemical equilibrium
This study presents a method for teaching the subject of chemical equilibrium in which students engage in self-learning mediated by the use of a new multimedia animation (SEQ-alfa©). This method is presented together with evidence supporting its advantages. At a microscopic level, the simulator shows the mutual transformation of A molecules into B molecules and vice versa for the reversible one-step chemical reaction, A(g) ⇔ B(g). The user defines the reaction as endothermic or exothermic and sets a given reaction temperature; SEQ-alfa© then calculates the kinetic constants of the forward and reverse reactions. Based on initial given concentrations, the animation then evaluates the respective rates and concentrations, as well as the concentration quotient value, as the reaction progresses towards its equilibrium state. SEQ-alfa© also demonstrates the effects of concentration and temperature alterations on the reaction's progress and the value of the reaction quotient until equilibrium is reached, thus giving the equilibrium constant. In addition, a validation of this new approach was carried out with 27 teachers. A pre-test and post-test of students’ understanding of the basic concepts of chemical equilibrium were conducted. Tested groups attained a 50% average learning gain (nexp = 130, nctrl = 26). Those students with little or no previous knowledge acquired a better understanding of chemical equilibrium. In addition, 80% of teachers agreed that the multimedia resource and its complementary activities had positive effects.