Students’ understanding of acid, base and salt reactions in qualitative analysis

Abstract

A two-tier multiple-choice diagnostic instrument was used to determine 915 grade 10 students' (15- to 17-year-olds) understanding of the acid, base and salt reactions involved in basic qualitative analysis. The results showed that many students did not understand the formation of precipitates and complex salts, acid-salt/base reactions and thermal decomposition involved in qualitative analysis. This indicated that the usual method of teaching the topic might be ineffective in fostering its understanding. In response to this, an instructional package which emphasised the three levels of representation of the reactions was developed.