Virtual chemistry laboratory modules were investigated as a potential learning resource that complements traditional in-person experiments. In collaboration with a high school instructor, we designed two interactive modules, "Rates of Reaction" and "Models of Organic Molecules," which became part of a previously reported online chemistry platform referred to as LabLessons. High school students took advantage of these modules to reinforce their knowledge of specific chemistry concepts and prepare themselves for the corresponding lab experiments. Students and the instructor were surveyed after their use of the two modules, providing feedback on the module designs and effectiveness. Survey results as well as academic performance suggest that independent learning through modules had an overall positive impact on learning when used in conjunction with traditional methods.