Teaching chemistry of water purification in grade 11 using locally available materials through the scientific inquiry approach

Abstract

This dissertation surveyed the validities of teaching the chemistry of water purification in South African schools using locally available materials (LAM) through the scientific inquiry (SI) approach. The researcher randomly selected four secondary schools that provided a small and purposive study sample of thirty-two Grade 11 learners and four teachers. The research design applied a mixed-method approach, consisting of qualitative and quantitative methods of data collection. Within this approach, the outcome of SI instruction that integrated LAM was compared with that of conventional instruction through a quasi-experimental control groups design. The researcher identified in the analysis of interviews and questionnaires the most complex aspects of the chemistry of water purification for learners to understand as redox reactions, acid-base systems, precipitations, and chlorination. However, the use of LAM through the scientific inquiry approach made it easier for learners to understand the concepts. The high mean scores ( =80.88; SD=10.28) in Research-based Test 2 (RBT2), of the experimental groups taught through SI signified that those learners immensely benefited from an active and collaborative learning environment. The lowly scores ( =61.69; SD=4.21) of control groups could be attributed to a linear and passive participation of learners in the conventional classroom instruction. The marks of the two groups in post-test RBT2 were paired and contrasted using GraphPad software. The results showed that t =6.699, df =21 with a significant value of 0.0001, which is less than 0.05 (p<0.05), hence it can be inferred that the difference between the means of the two groups was not only statistically important but also worth an explanation. The higher performance scores in RBT2 and the Rubric Assessment Tool (RAT) in experimental groups represents that the intervention was successful in the implementation of instructional design in the the study. In addition, the learners had mastered the crucial aptitudes that included self-discipline in understanding, cooperative learning, searching relevant text on topic, hands-on or laboratory practice and logical thinking in problem solving by working through the SI activities that used LAM.