The research was conducted in the period from March to June 2019 to address the prevalence of misconceptions among primary school students regarding the acids and bases concepts and to design appropriate interventions. The sample consisted of 470, 8 th and 9 th grade students from seven schools in Macedonia, divided into two groups: a control group (CG) and an experimental one (EG). The students' conceptual knowledge was examined, on the basis of which the students were divided into 4 groups: satisfactory conceptual understanding, roughly adequate performance, inadequate performance, and quite inadequate performance. Both quantitative and qualitative methods were included to conduct more comprehensive research and obtain more relevant results. The analysis of the pre-and post-tests showed significantly better results in the experimental group indicating the efficiency and applicability of the teaching intervention. Several misconceptions were detected among the students, but they were reduced or eliminated after the applied intervention.