Thermochemistry multiple representation analysis for developing intertextual learning strategy based on predict observe explain (POE)

Abstract

This article was written to describe the results of multiple representation analysis of concepts related to thermochemistry topic. The study was set under a qualitative method. It was found from the analysis of five General Chemistry textbooks that thermochemistry consists of three major concepts which include exothermic reaction, endothermic reaction, and enthalpy change. In macroscopic level, exothermic reaction was presented by several phenomena such as Ca(OH)2 production. Meanwhile, endothermic reaction was presented by Ba(OH)2.8H2O and NH4Cl reaction. In the sub microscopic level, all textbooks explained the concept of exothermic and endothermic reaction by using descriptive approach showing that reaction happened and followed by heat change. In addition, in symbolic level, the explanation was enriched by the use of chemical reactions equations, diagrams of energy level and the visualization of the system in releasing or receiving the heat. The macroscopic representation for concept of enthalpy change was presented as an experiment using calorimeter which then described by sub microscopic representation that the energy released is equal to the energy system accepted by environment. Last, in symbolic level, the explanation was enriched by the use of formula to calculate the enthalpy change. This finding was used for developing intertextual learning strategy based on POE.