The Level of Mastery of the Concept of Chemical Reaction Rate by 9^th Grade Students

In this paper, we focused on the results of research, which we have conducted to ascertain the knowledge of Slovak students who have just finished their lower secondary education concerning the topic of chemical reaction rate. The study was attended by a total of 320 15-year-old graduates of basic chemistry education belonged to several schools. Students’ knowledge was found through didactic test consisted of 1 item related to clustering and several two-level tasks. The results were analyzed in terms of deeper insight into the students’ understanding of the issue and students’ misconceptions were also identified. The findings related to the problems connected with acquiring the concept of chemical reaction rate, especially in relation to the students’ grasp the mentioned topic at submicroscopic, macroscopic and symbolic levels of representation were analyzed. We managed to investigate the students’ various difficulties associated with mentioned topic. Several problems were found. Students have a problem with understanding the basic term “chemical reaction rate”, relating it to bodies in motion, which they know from physics lessons and everyday life. They also have problems to distinguish and interconnect information at different levels of representation. Students often do not know which factors affect the rate of reaction and how. They do not understand the concepts of concentration and catalyst and do not distinguish the terms temperature and heat. Students’ knowledge is often only formal and lacks a real conceptual understanding of the problem. Their solving of problems does not go beyond the algorithmic level of solution and they are not able to solve tasks that are not typically school-related issues.