Fostering Scientific Reasoning Competencies in Undergraduate Laboratories Using “Classical” Kinetics Experiments

Scientific reasoning competencies enable students to engage in scientific inquiry through a wide range of methods, for example by asking questions, formulating hypotheses, and planning, carrying out, and evaluating experiments. Laboratories are particularly suitable to foster these competencies in higher education. In order to give lab educators the opportunity to foster scientific reasoning competencies, we present a learning sequence consisting of four established experiments in the field of kinetics. These include investigating reaction rate dependencies, for example of the reaction between sodium thiosulfate solution with hydrochloric acid solution depending on concentration and temperature and of the reaction between potassium peroxodisulfate solution with potassium iodide solution depending on the choice of catalyst. As a curricular innovation, these classical kinetics experiments are implemented in a manner that students have to reason scientifically including the control of variables strategy. The experiments are sequenced using the steps of confrontation, acquisition, application, reflection, and transfer. Deploying measures of learning support, this sequence allows students to develop a multitude of scientific reasoning skills, helping them to meet an increasing number of quality criteria of scientific investigations for ensuring the validity of their experimentation. We coded the lab reports with regard to fulfilled quality criteria based on a pre- and postevaluation design (N = 46). The results confirm significant gains in students’ scientific reasoning competencies.