The purpose of this paper is to explore and explain students' achievements in solving context-based gas exercises comprising the macroscopic and submicroscopic levels of chemical concepts. The influence of specific variables, such as interest in learning, formal-reasoning abilities, and visualisation abilities, is a significant factor that should be considered when explaining students' achievements with context-based exercises. Seventy-nine students of three age groups (12, 16, and 23) participated in the study. Questionnaires, tests, and a semi-structured interview including computer-displayed context-based exercises were used to collect data. In addition, an eye-tracker was used to determine the exact location of the participants' points of gaze. The results show that students on average answered correctly from 40 to 79% of all questions in the context-based exercises. The context-based exercise related to air compression is indicated as being difficult for students. In students' explanations of different levels of chemical concepts, representation difficulties are detected in all three age groups of students. Students' achievements in solving context-based gas exercises do not depend on interest in learning chemistry and visualisation abilities. However, statistically significant differences exist in total fixation duration on the correct submicrorepresentation animation between students with different formal-reasoning abilities. The results serve as a starting point for the planning of different context-based exercises and problems comprising the chemistry triplet with 3D dynamic submicrorepresentations.