The goal of this study was to assess students' level of conceptual understanding of chemical kinetics and equilibrium using topic-specific pedagogical content knowledge (TSPCK)-based instruction in chemistry grade 11 students. The research was a mixed approach that involved 159 grade 11 chemistry class students from Addis Ababa administrative city, Ethiopia, and employed a mixture of qualitative and quantitative methodologies. Purposive sampling was used for the sample procedure and four intact classes were selected as three intervention groups and one control group: curricular saliency-based, representation-based, conceptual teaching strategy-based instruction, and comparison groups. The level of conceptual understanding was assessed using reasoned questions, specifically a two-tiered multiple-choice pretest, and posttest. The findings revealed that students' conceptual understanding of chemical kinetics was higher than that of chemical equilibrium concepts. According to the findings of the students' pretest and posttest, the level of conceptual understanding increased from 27.08% to 32.21% in chemical kinetics and from 15.91% to 23.68% in chemical equilibrium. Overall, representation-based instruction and conceptual teaching tactics boosted students' conceptual knowledge and accomplishment in chemical kinetics and equilibrium concepts. This study proposes that the level of conceptual understanding of grade 11 students in chemical kinetics should take into account the horizontal relationship between mathematics and the chemical kinetics concepts, which should be taught using technology-assisted teaching strategies such as conceptual teaching strategies and three-fold mental representations.