Investigating the misunderstandings of 12th grade students in acid-base concepts through a three-tier diagnostic test

The purpose of this study is to investigate the misunderstandings of twelfth grade students in the subject of acid-base. The statistical population of this study is equal to the quantity of the twelfth grade students of two schools in Rasht who are studying in the fields of experimental sciences and mathematics-physics in the academic year 1399-1400. The statistical sample consists of 47 students who were randomly selected. As a data collection tool, a four-choice three-row acid-base diagnostic test was designed and used. To analyze the data, the appropriate method was used with a three-tier test and students' perceptions were examined in three categories: scientific understanding, lack of understanding and misunderstanding. The results revealed some misunderstandings of acid-base concepts in students. Students are misunderstood, from more to less frequency, in the concepts of electrolyte, concentration of hydronium ion in dilute acidic solution, neutralization reaction, differentiation of decomposition concentration and acid equilibrium concentration, detection of acids and bases, ionization and separation concepts, ionization degree, ionization of several acids Protonates and misunderstandings of the concepts of strength and acid concentration. Identified misunderstandings can be used to improve teaching-learning methods and provide appropriate educational content.