Research on student argumentation in chemistry laboratories has mainly focused on evaluating the quality of students' arguments and analyzing the structure of such arguments ("i.e." claims, evidence, and rationale). Despite advances in these areas, little is known about the impact of activity framing on the nature of student argumentation in laboratory settings. In this research study, we analyzed the arguments generated by college organic chemistry students working on a substitution reaction experiment that was framed in two distinct ways: predict-verify and observe-infer. The arguments constructed by students in their post-laboratory reports under each laboratory frame were characterized by paying attention to both domain-specific and domain-general features. Our analysis revealed significant differences in the chemical concepts and ideas that students under the two conditions invoked, as well as in the level of integration, specificity, alignment, and type of reasoning observed within and across different argument components. Our findings highlight the importance of paying attention to how experiments are framed in terms of the goals, procedures, information, and tools available to students as these decisions can have a major impact on the nature of the claims students make, their use of evidence, and the approach to reasoning that they follow.