Reasoning with molarity
Keywords:
molarity, conceptual understanding, reasoningAbstract
Within the framework of studies that compare the resolution of conceptual versus algorithmic problems, an instrument is presented for a conceptual approach to molar concentration, which focuses on reasoning on macroscopic properties of solutions The results, obtained from the survey carried out on 76 university students, show that they present greater difficulties in the case of the inverse proportionality between molarity and volume of dissolution, if a constant number of moles is considered. Interviews were conducted with 16 students, with the technique of thinking aloud. The answers (reasoning and strategies) were classified into four categories. An important finding of this research is that many students confuse number of moles with molarity, and use these concepts interchangeably. This instrument, which stimulates thinking, is motivating for both students and teachers and can be used in different teaching instances.
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