<p>Empowering student participation in the classroom by considering the domains of scientific knowledge creates opportunities for interaction with subjects, knowledge, values, practices, and materials that promote learning. This qualitative study examines a remote teaching activity where students from a Chemistry Education degree program explore Organic Chemistry reactions. Our analysis reveals that when students position visual representations as epistemic objects, they mobilize the material domain of scientific knowledge, which facilitates the emergence of conceptual, epistemic, and social domains. The mobilization of these domains specifies the build of epistemic practices unique to Organic Chemistry, such as the use of visual representations. In turn, this epistemic practice contributes to other practices, including predicting relevant aspects of the phenomenon, determining conclusions about the phenomenon, and reconfiguring objectives. We conclude that the positioning of visual representations as epistemic objects characterizes their use as an epistemic practice. The results presented can inform teaching work that aims to mobilize domains through the build of epistemic practices by students in their own context. As a contribution to research in Science Education, we propose the scientific knowledge domains as a novel framework for analyzing epistemic practices.</p>