The Dynamic (Organic) Chemistry Laboratory Part I

1) Instead of one single experiment repeated by all the students, three or four different variations of the same experiment can be performed by different students during in the same lab. For example, the oxidation of cyclohexanol to cyclohexanone is expected to yield identical results for every student every year. However, the oxidation of 2, 3, and 4-methyl-1-cyclohexanol positional isomers can be done under identical conditions but will yield a more intriguing set of results. In this case, students can compare and contrast their results with their classmates a meaningful way. In fact, the Aldrich catalogue is filled with secondary alcohols that could be oxidized with minor changes in procedure. Almost every “traditional” experiment can be redesigned to investigate a cluster of related experiments. For example, the hydrodistillation of cloves yields an essential oil with a high proportion of eugenol. However, any spice can be hydrodistilled to yield many different essential oil combinations that can be analyzed by gas chromatography.

2) Include results from previous years’ experiments as part of this year’s data set. A year-to-year comparison of TLC Rf values gives a more meaningful data set than just looking at one student’s results in isolation or even this year’s class data. Data compilation can be spatial as well as temporal. This year’s class data can be compared with this year’s data generated at another institution.

3) Once data sets are created, stress statistical analysis as a way to interpret results. Larger data set indicate general trends and invite deeper analysis. Students can determine whether their results fit within a standard deviation of the class data. An expanded inquiry can be performed to determine whether the current class data fits within a standard deviation of the historical class data. Data analysis also gives insight into the reliability of the technique and/or the data gathering method. For example, students rating solubility of a compound in a given solvent as insoluble, somewhat soluble, soluble, or very soluble gives a wide range of answers.

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