Simple Distillation, Gas Chromatography

Adrienne Wagner

Jordan Lamb

October 25, 2016

Experiment 8: Simple Distillation, Gas Chromatography

Purpose:

        This experiment was performed to prove whether or not Isopentyl acetate contained at most 10% isopentyl alcohol and no more than 2% acetic acid. A company needed to find an alternative banana flavor due to all of their banana trees being destroyed by Hurricane Floyd. They tasked the chemists to see if Isopentyl Acetate was within their restrictions for isopentyl alcohol and acetic acid.
Procedure:

        150 mmol of isopentyl alcohol was measured and mixed with 17 mL of glacial acetic acid and 1 mL sulfuric acid, then stirred. The mixture was heated for one hour and then cooled to room temperature. The solution was washed using a separatory funnel, 25 mL of water, aqueous layer drained, 25 more mL of water, drain again, and finally 30 mL sodium bicarbonate was added and drained twice. 1.3 g magnesium sulfate was used to dry the solution. The mixture was distilled and the boiling point was measured.  

Data, Calculations, and Results:

Discussion and Conclusion:

Assigned Questions:

1. A. The minimum amount of boiling water needed to dissolve 0.200 g of phenacetin is 16.393 mL.

B. Approximately 0.0125 g of phenacetin will remain dissolved in the water at room temperature.

C. The maximum amount of recoverable phenacetin is 0.1875 g.

2. Compound X is most likely phenyl succinate because the melting point of the mixture (120°C) is the closest to the actual melting point of the parent substance (121°C).

3.

A. You failed to dry the product completely: The yield would not be effected at all because the same amount would be present; the purity of the product would be lower though because the water would dilute the product.

B. You used enough water to recrystallize phenacetin, but your unknown was acetanilide: More acetanilide would stay in the water, making the yield lower. The purity would be higher because there would be more impurities in the solution

C. You didn’t extract all of the aspirin from the dichloromethane solution: The purity would be lower because dichloromethane would be present.

4.

A. You failed to dry the product completely: The melting point would not change because the substance would not change.

B. You used enough water to recrystallize phenacetin, but your unknown was acetanilide: The melting point would not be effected.

C. You didn’t extract all of the aspirin from the dichloromethane solution: The solution would have impurities because of the undissolved dichloromethane, so the boiling point would be lower.

Experiment 23: Extraction of Iodine by Dichloromethane

        When 2 mL of Iodine and 2 mL of dichloromethane were combined, two distinct layers were visible. Initially, the top layer was a dark-red/brown color and the bottom layer was light pink. When the mixture was shaken and vented, the two layers combined slightly resulting in the top layer being dark-pink/purple and the bottom layer turning dark brown. The dichloromethane layer was removed and the top layer was dark-red/brown and the bottom layer was light pink. The mixture was shaken and vented again and the top layer turned an opaque dark-brown/maroon and the bottom layer turned a non-opaque dark red.