DYSLEXIC STUDENTS IN CHEMISTRY CLASSES: THEIR DIFFICULTIES WITH CHEMICAL FORMULAE

Abstract

The aim of this preliminary study was to investigate whether dyslexic students encounter difficulties with the use of chemical formulae, in particular structural formulae. Two groups of final-year, upper secondary students (grade 12) were studied: a control group, consisting of 32 normal learners (17 boys and 15 girls), and an experimental group of 5 dyslexic students (3 boys and 2 girls). All students had to solve numerical exercises on colligative properties. In each exercise, a student had to replace in the corresponding colligative-property equation the value of the molecular weight of the solute. Molecular weight had to be determined either from the molecular formula or from the structural formula of the compound. The findings of the study showed that dyslexic pupils had lower scores in the reading of both molecular and structural formulae. The wrong estimation of molecular weights resulted from: (a) omission of atoms; (b) omission of subscripts; (c) misreading them. The findings indicate that, if there are dyslexic students in a class, we must be very cautions with the use of chemical formulae. [Chem. Educ. Res. Pract. Eur.: 2000, 1, 277-280]