A web based learning module has been developed to assist students in the preparation of the laboratory report for the liquid chromatography experiment in an instrumental analysis course. This experiment has the students carry out an active ingredient assay of the constituents of ExcedrinŽ. Due to the lack of equipment in the laboratory course students must rotate through the various experiments. The theory of this lab experiment is taught in the last three weeks of the quarter and by this point almost all the class has undertaken the laboratory work. The tutorial carries the students through the logic of the required calculations and while in this process, the student is challenged with questions that encourage active learning. Possible answers that anticipate common errors are provided and the incorrect selections bring the student to pages that explain the fault in the logic in getting to that answer. Feedback is provided immediately and students that are more capable are able to pass rapidly through the exercise while those needing additional help are directed to pages that provide that help.