The purpose of this study was to investigate senior high school students' difficulties predicting the existence of hydrogen bridge bonds between organic molecules, investigate students' difficulties predicting the relative boiling points of simple organic compounds, and develop test questions that enable teachers to quickly get information about their students' difficulties. Fourteen free-response and multiple-choice questions were administered to 4,846 senior high school students. Students were not only asked to check an answer they regarded as correct, but also to give a reason for their choice. Results indicated that students' understanding of intermolecular forces is not precise enough. They did not consider all criteria that were necessary to predict whether molecules form hydrogen bonds. Students also had difficulties predicting the relative boiling points of unbranched and branched alkanes, mainly because they used the chain length as a criterion for their prediction. The study shows that systematic development of test items is crucial to avoid students using incorrect strategies to arrive at the correct answer. Tests that do not meet this criterion could produce misleading results. The multiple-choice items developed in this study can assist in the process of helping teachers use the findings of research in the classroom. (Author/MKR)