Prior to the discovery and application of spectroscopy techniques to determine the structure of an organic compound, the structure was determined by using a series of chemical tests to identify the functional groups in the molecule and how they were connected. The tests were often rapid and simple to to perform in a test tube, and gave a visual indication, i.e. a color change or formation of a precipitate. It was also common to break the molecule into smaller fragments which are easier to identify.
While these techniques have been replaced by the much faster spectroscopy techniques, they are a good test of your understanding of how molecular structures are transformed during chemical reactions. It is also a good test of your deductive reasoning skills.
The following pages have examples of the common chemical tests and explain how they would be used. Be sure you have a good understanding of the tests before moving to the questions. Chemical tests: by name or by functional group. There are also flow charts of how the tests would be applied in the lab.
The table below provides links to the questions. I have made use of the JSME (JavaScript Molecular Editor). If you are unfamilar with this "applet" please see the Learn to Smile page. You can use the editor to draw the structure for any specific molecule, then click on the benzene icon with the blue arrow in the bottom right corner of the drawing "applet" and drag the structure to the correct answer box.
Compound Number
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