Sample Quiz for the Oxidation of Alcohols Experiment

Besides the types of questions below, questions on handling of wastes and on lab etiquette will be included on all prelab quizzes. Also, know how to handle IR salt plates.

1) Compared to the dichromate oxidizing agents, hypochlorous acid (prepared from household bleach) is:

1. safe
2. inexpensive
3. environmentally sound
4. all of the above

2) Cyclohexanol is:

1. an irritant
2. extremely flammable
3. a carcinogen
4. all of the above

3) In this experiment, which species is oxidized?

1. cyclohexanone
2. cyclohexanol
3. hypochlorous acid
4. acetic acid

4) Before the aqueous reaction mixture containing the product is extracted into the organic solvent, methylene chloride, solid NaCl is added. The purpose of this inorganic salt is to:

1. decrease the solubility of the organic product in water
2. lower the boiling point of the water
3. cause the water to be immiscible with the methylene chloride
4. raise the density of the aqueous layer so that it will be on the bottom in the extraction

5) After reaction and neutralization and salting-out, the aqueous layer is extracted with methylene chloride. The product will be in the _________ layer, which will be on _________ .

1. aqueous, top
2. organic, top
3. organic, bottom
4. aqueous, bottom

6) If you begin with 2 mL of cyclohexanol, how many mLs of cyclohexanone would be a 100% theoretical yield?

7) The presence of excess hypochlorous acid is monitored by testing the solution with KI-starch test paper. How will you know if the test is positive?

1. the paper will turn red
2. the paper will turn black
3. the paper will not change in color
4. match the tested paper with the posted standard color changes

8) Would the following compound be oxidized by hypochlorous acid (HOCl) and, if oxidation occurs, what would the oxidation product be?

1. yes
2. no

9) A student prepared cyclohexanone as you will do in this experiment. The IR looked pretty good, although there was a sharp band at 1292 cm^-1. The TA ran an NMR of the product and obtained the spectrum below. What can you conclude about his product?

(for your reference, links to the NMR spectra of cyclohexanone and cyclohexanol)

1. the product contains cyclohexanone contaminated with a solvent, probably methylene chloride
2. the product is pure cyclohexanone
3. the product is pure cyclohexanol
4. the product is cyclohexanone contaminated with cyclohexanol

In an IR spectrum, where are IR bands that represent alkene compound stretches?
How would the ¹H-NMR of cyclohexene differ from that of cyclohexanone?

Answers.