This work is part of a larger project that seeks to understand how students blend (integrate) chemistry and mathematics as they work through chemical kinetics problems. Here we focus on four students from our larger sample: two students that demonstrated more instances of blending chemistry and mathematics in their interviews ("high-frequency blenders") and two students that did not have any instances of blending chemistry and mathematics in their interviews ("nonblenders"). In this study, we characterized the intuitive mathematical ideas the students associated with equations (symbolic forms) and graphs (graphical forms), focusing on how the students' mathematical reasoning influenced their understanding of chemical phenomena. The findings suggest that, in order for students to integrate chemistry and mathematics in a way that supports their understanding of the chemical processes in chemical kinetics, they must be able to reason using symbolic and graphical forms.