Conceptions of Gases and Stoichiometry Held by the Awardees at the National Mathematics-Science Competitions (Chemistry)

Abstract

Conceptual understanding about stoichiometry, gas laws, and diffusion of 56 middle and high school students, who were awarded at the chemistry division of the 6th National Mathematics-Science Competitions and participated in a summer school of Korean Chemical Society, was studied with five essay type questions and their corresponding multiple choice questions. Misconceptions and the characteristics of problem solving approaches were identified. Students had fairly good understanding on stoichiometry, but exhibited many misconceptions on gas laws and diffusion. Their success rate in the multiple choice question regarding gas laws was less than 70%. For the multiple choice question regarding diffusion, the success rate was significantly lower than that of the corresponding essay type question, and a negative relationship between grade and success rate was observed. Although students often used college level chemistry concepts and algorithmic problem solving to answer these conceptual questions on basic chemistry concepts, many concepts and formulas used were not consistently and hierarchically related to the basic concepts.이 연구는 서울대학교 사범대학 발전기금으로 이루어졌음