Describes four chemical terms that students with well-considered reasons use in a way that is not accepted in chemistry. From 4300-7500 senior high school students completed a series of multiple choice tests while other groups of students participated in discussions about the problem situations. Contains 34 references. (DDR)

The purpose of this descriptive study was to create and test questions on stoichiometry with number ratios for quick mental calculations and to identify students' problem-solving strategies. The present study was a component of a more comprehensive investigation in which 7,441 German senior high school students were asked to work on 154 test items…