ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 64, Number 1
JKCSEZ 64(1)
February 20, 2020 

The purpose of this study was to identify the problems faced by students in sub-microscopic representation of acid-base reactions. Herein, we selected 30 students of 12th grade science classes, who had studied various acid-base models. In order to investigate the sub-microscopic representation ability of the students, we developed nine items related to various contexts, such as one type of solute and solvent, two types of solutes and solvent, cases with water as solvent or with nonaqueous solvents. For all items, we consistently observed lack of concept of chemical change. In context of aqueous and nonaqueous solutions, the frequency of lack of concept of chemical bonding was high if ammonia was the solute or solvent. Moreover, the frequency of lack of concept related to the degree of electrolytic dissociation was high. Therefore, chemistry teachers should understand that students’ ability to sub-microscopic representation of acid-base reactions can be enhanced by analyzing the difficulties faced by the students in solving diverse acid-base problems.