Development of Teaching and Learning Material for Chemical Formulae and Chemical Equations

Abstract

The West African Examinations Council has since the year 1994, alluded consistently to students inability to write correct chemical formulae and chemical equations at the SSSCE/WASSCE chemistry examinations. Studies have also shown that the ability required to write chemical equations is not a simple one and that, students’ persistent difficulties in solving stoichiometric problems are partly associated with their inability to write correct chemical formulae and represent chemical equations correctly. Hence, this study developed a teaching and learning material for chemical formulae and chemical equations of inorganic compounds. Three form 2 and three form 1 science classes selected from the Cape Coast Metropolis for the 2012/2013 academic year were initially sampled randomly for the pre-test and after the pre-test, one form 2 and one form 1 science classes were selected for the development of the teaching and learning material. The two main designs used in this study were cross-sectional survey and one group pre-testpost- test experimental design and the two main instruments used were achievement tests and an open ended questionnaire. One of the key findings was that the concept of valency and the role it plays in the writing of chemical formulae was poorly understood by both form 1 and form 2 science students. Also, the teaching and learning material developed in this study helped improve the conceptions and performance of the students as the mean vales of all the posttests in this study were significantly higher than their pre-test mean values. One recommendation urges chemistry teachers to use charts of the periodic table and oxidation numbers when teaching chemical formulae and chemical equations.