Inconsistent Language Use in Online Resources Explaining the Mole Has Implications for Students’ Understanding

Abstract

The quantity amount of substance (symbol “n”) and its SI unit, the mole (symbol “mol”), are unfamiliar to novice chemistry students. Developing a good understanding of this quantity and its unit has previously been demonstrated to be problematic. In this paper, we analyze 14 different online resources in terms of how they define and apply the mole. Our findings show widespread use of the mole as a quantity rather than as a unit in mathematical expressions as well as in text. This leads to the absence of reference to the quantity amount of substance and is inconsistent with how other quantities (such as mass) and their units (g) are represented. This practice is also evident in wider pedagogic contexts and can cause confusion for students developing understanding of the mole. We provide recommendations to address this issue through the consistent use of the mole as a SI unit for the quantity amount of substance.