Abstract:

Many schools in South Africa are situated in resource disadvantaged environments which do not have chemistry laboratories or any chemistry equipment. Students from such schools when entering their first year at university to study chemistry have difficulty with many of the fundamental concepts essential to understanding the subject. By investigating student’s understanding of chemical behaviour the teaching approach can be adapted to accommodate these shortcomings.

A standardised chemistry concepts test (CCT) developed by Professor Marietjie Potgieter has been used to assess the level of understanding of first year Chemistry students at Tshwane University of Technology (TUT) since January 2010. Several interventions have been used to overcome identified difficulties and the purpose of this paper is to present the results achieved when the different ways students describe chemical behaviour are used to overcome observed conceptual misinterpretations.

One of the questions in the CCT required students to use a balanced chemical reaction equation to express what they believe occurs at the molecular level. This question was targeted because students recorded the lowest scores every year both on pre- and post - tuition testing. In order to maintain the integrity of the CCT different reaction equations were used.

Students were given worksheets to complete where using a balanced chemical reaction equation they were required to draw molecular representations of both reactants and products in separate solution compartments. Molecules of solution were to be excluded and the required pictures were intended to illustrate whether students really understood the following concepts:
• Proper dissociation of substances.
• Correct bonding and structure.
• Conservation of matter.

After completion of worksheets students were divided into groups to discuss between their peers the different answers within their group. The results of this student interaction and what was learnt about how students understood the concepts will be presented in the paper.

Keywords:

Chemical reactions, bonding and structure, conservation of matter.