The role of practical work in teaching physical chemistry

Abstract

Changes in attitudes towards chemical education and changes in physical chemistry itself invite a re-examination of the role of practical work in the teaching of physical chemistry. Several functions of laboratory work in physical chemistry are readily recognized. First, it gives opportunity for the student to acquire manipulative skills and secondly provides experience in making observations in a critical manner. At the same time the student may gain knowledge of a variety of experimental techniques. But besides these bench-skills practical work offers opportunity to develop other abilities in the student. The reporting and interpretation of results, and the presentation of scientific work can all be put in a realistic context for the student. Nor do the functions of practical work end here. After some experience the student may take a larger part in the design of experiments. Then there is the possibility of some investigational studies or a small research project to consider. All of these are widely recognized as important features to be considered in the design of courses in practical physical chemistry, but the relative importance of these various functions changes as physical chemistry itself develops. Considering a knowledge of techniques first it could be argued that there are some techniques (e.g. the use of vacuum lines) which are now so important in physical chemistry that every student should have some experience of them. On the other hand so many techniques are now employed in physical chemistry that an undergraduate course can cover only a fraction of them. Of the new instrumental techniques that are being introduced into chemistry we find increasingly that they are at the same time both more sophisticated and simpler. Very similar boxes with very similar knobs and meters replace different varieties of string and sealing wax. These developments have repercussions throughout chemistry. They change the position markedly in a physical chemistry teaching laboratory. Only twenty years ago the member of academic staff in charge of a physical chemistry laboratory could be familiar with the detailed construction of every piece of equipment, mechanical, electrical, optical or electronic. He could locate any fault that might arise and correct it. Frequently he expected students to develop the same attitude towards the instruments they used. But the introduction into the physical chemistry teaching laboratory of the mass spectrometer, the infra-red spectrometer, or even the packaged conductance bridge or direct-reading pH meter have changed all this. Indeed instrumentation is no longer confined to the physical laboratory. Increasingly, instrumental techniques are being employed in inorganic and organic teaching laboratories. It is likely in the