Effective learning in chemistry education requires students to understand visual representations across multiple conceptual levels. Essential to this process are visuospatial skills which enable students to interpret and manipulate these representations effectively. These abilities allow students to construct mental models that support problem solving and decision making, improving their understanding of complex concepts, for example chemical structures and reactions. The impact of individual differences in mental imagery, such as aphantasia and hyperphantasia, on chemistry students' spatial thinking when engaging with visual representations is not well understood. This paper presents two exploratory studies that examine how the vividness of mental imagery is related to student outcomes in chemistry-related visuospatial problem solving. The first study quantitatively assessed the performance of first-year university students in tasks requiring complex visual and spatial reasoning within a chemistry context. The second study, involving the same participants, used qualitative interview data to investigate their cognitive strategies with a focus on how their mental imagery impacts their problem-solving approaches. Preliminary results suggest that the vividness of students' visual mental imagery did not significantly impact their ability to spatially reason with visual representations in chemistry. Our findings also indicate that students with aphantasia may employ alternative strategies that mitigate their lack of visual mental imagery. This paper highlights the need for further research into the diversity of cognitive mechanisms employed by chemistry students of varying mental imagery capabilities.