Laboratory Examination in General Chemistry The laboratory examination described here was developed and administered to approximately 200 students of General Chemistry. At the Tulane University the first semester of general chemistry does not involve any laboratory; the second semester includes 4 hours of laboratory per week. The experiments during the spring semester 1978 included: Qualitative analysis, 5 weeks; Vapor density and molecular weight, 1 week; Standardization of NaOH by making up a standard solution of oxalic acid, 1week; Equivalent weight of an unknown acid, 1week; Volumetric estimation of iron, 1week; Rates of reactions, 1 week; and Synthesis of ca-ordination compounds, 2 weeks. The laboratory examination was designed to test the students' ability to perform the experiment in a given time, obtain accurate results, and complete the calculations. It consisted of a written quiz during the first fifteen minutes, then the performance of an experiment which was a quantitative estimation followed by qualitative analysis of an unknown solution for cations. Finally the student completed the calculations and wrote a report including notation of the reagents used in qualitative analysis and the ions found to be present or absent. The average time required for this examination was 4 hours; fast workers required a little less and slow workers required a little more. The student prepared for this examination by studying all the experiments he had performed during the 12 laboratory periods including qualitative analysis. The 15-min quiz consisted of a question based on any of the quantitative estimations he has done during the semester. There was a question on the experimental procedure for either one of the listed experiments directly or for an experiment based on the procedure or procedures known to him. In the latter ease he might have to use his ingenuity. In the spring semester examination, iron estimation was assigned. The question for the initial quiz was In the first 15 minutes write a brief procedure far the experimental determination of (1) iron in the Fez+ farm and (2) iron in the Fe3+form in the solid mixture of unknown given to you. You are provided with standard solution of K~Cr207, 6M HCI, saturated mercuric chloride solution, 0.5 M SnCln,and diphenylamine indicator. 'I'hr answer shrcL: %,errcnllr.
