In practical sessions students lack sufficient time or opportunity for deep processing of information. If the signal to noise ratio is too low, it can obscure the 'chemical message' which the lecturer is trying to convey. This study reports on an action research driven attempt to improve on a Hess's Law experiment, well known in most first year curricula. Data collected in 2000 indicated that students struggled primarily because there were toomanypractical demands to allow them to focus on the concepts involved. The exercise was thus divided into two sessions in 2001, the first to address the issues related to techniques required, the second, similar to the experiment in 2000. Analysis of data collected in 2001 shows that the changes made a significant impact on the effectiveness of the laboratory session.
South African Journal of Chemistry Vol.56 2003: 47-53