1. **Describe the chemical tests and what they tell us.**

2. **Provide an explanation for a negative iron(III) test with eugenol.**

3. **How might the IR spectrum look differently if one skips the drying step in the procedure?**

4. **Describe the difference between steam distillation and simple distillation.**

5. **Describe what result you would expect if one employed a fractional distillation apparatus in this experiment.**

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### A. Steam Distillation

1. Place approximately 10 g of crushed or ground cloves into a 250 mL round bottom flask. Fill the distillation flask about half-full with deionized water. No boiling chip is necessary as the mixture is heterogeneous.

2. Assemble a steam distillation apparatus and begin heating the mixture at a low setting to 80 to 90°C, using a heating mantle that can be easily removed if the distillation flask overheats. Allow the cloves to steep for about 10 minutes. There should be no distillate collecting at this point; it is okay if the water is gently boiling. This step allows the cloves to hydrate and soften to improve extraction; skipping this soaking step will result in low recovery.

3. Gradually heat the mixture until it begins to boil and distill over. A good rate of distillate collection is 2 to 3 drops per second. Record the temperature at which the distillate collects.

4. Do not heat the solution to dryness; periodically add a few milliliters of pure water from the separatory funnel. Keeping the round-bottom flask about 1/2 to 2/3 full throughout co-distillation will yield the best results. The distillation mixture will froth during the distillation, especially in the early portions. Do not allow the distillate to boil over into the Claisen head and contaminate the distillate.

5. Continue the distillation until you collect approximately 75 mL of distillate, using a 100 mL graduated cylinder. Take note of the appearance and aroma of the distillate. This should take approximately 1 hour. Collecting more distillate results in higher yields. Do not allow the mixture to overheat and boil over into the condenser.

6. Allow the distillate and apparatus to cool to room temperature.

### B. Extraction of Clove Oil

1. Transfer the distillate to a separatory funnel and extract using three 15 mL portions of dichloromethane. Dichloromethane is denser than water and should form the lower layer. For the first two portions, shake the separatory funnel vigorously. This may create an emulsion. If an emulsion forms, draw off the clear lower layer to the emulsion line for the first two extractions; shake the third portion less vigorously and allow a longer period for the layers to separate.

2. Combine the dichloromethane extracts in a clean and dry conical Erlenmeyer flask. Dry with anhydrous magnesium sulfate. Add enough drying agent so that it no longer clumps together. It should appear to settle as a dry powder. Cover the flask and occasionally swirl for about five minutes.

3. Decant the solvent into a clean, dry pre-weighed beaker.

4. Evaporate the dichloromethane on a hotplate at a low setting, while blowing a gentle stream of air across the top of the beaker using rubber tubing attached to the pressurized air-line in the fume hood. When the mixture no longer appears to be boiling and leaves behind viscous yellow oil, all of the dichloromethane has evaporated.

### C. Analysis of Eugenol

1. Determine the mass of the recovered clove oil.

2. Take note of the scent of the clove oil.

3. Calculate the percent mass recovered: \((\text{mass of clove oil} / \text{mass of cloves}) \times 100\%\).

4. Perform the bromine test and iron(III) chloride test on eugenol and other supplied compounds, taking note of any color changes. Dissolve the compound in 1 mL cyclohexane in a test tube, and add a few drops of the corresponding chemical for each test.

5. Obtain an IR spectrum of eugenol and identify any significant peaks in the spectrum.

### D. Clean-Up

Carefully disassemble the apparatus and clean all the organic glassware thoroughly! There will be clove residue on the glass. Soak for a few minutes with hot, soapy water before cleaning.