Fermentation and Distillation

General Chemistry 101/102 Laboratory Manual University of North Carolina at Wilmington

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Fermentation and Distillation

Purpose  To demonstrate the production of ethanol by the process of fermentation.

 Use the technique of distillation to separate a homogeneous mixture into its individual components.

Safety Considerations  Do not drink the alcohol you produce in this experiment!

 Discard the Ca(OH) 2 and paraffin oil in the labeled bottle in the hood. Flush all other materials down the drain with plenty of water.

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Fermentation and Distillation

Procedure  Place sugar, Pasteur salts, and deionized water into a 250 mL flask and swirl. Add yeast and swirl again.

 Fill a medium test tube 1/3-full with Ca(OH) 2 and add 5 drops of paraffin oil.

 Setup the apparatus as shown in the photo.

make sure end of tube is below paraffin oil

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Fermentation and Distillation

Procedure  Decant the fermentation mixture into a clean 250 mL flask.

 Setup the distillation apparatus as shown in the photo below.

 Gently boil the solution while collecting the distillate in the test tube. Collect about 6 mL of distillate.

glass tubing should end here

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Fermentation and Distillation

Procedure  Use about 4 mL of your alcohol to determine its density. Use the graph of Proof vs. Density to determine its proof.

 Place 10 drops of your alcohol in a watch glass and attempt to ignite it with your Bunsen burner. If it burns on its own, it is at least 40 proof.

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Fermentation and Distillation

Procedure  Each group will determine the mass of an assigned volume of bourbon. Record the mass and volume of your bourbon sample on the board.

 Using the class data, construct a graph of mass vs. volume for all the bourbon samples. Draw a “best fit” straight line through your data.

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Fermentation and Distillation

Procedure  Determine the slope of your “best fit” straight line. This is the density of the bourbon. Determine its proof from the Proof vs. Density graph.

D

Y slope =

D

Y

D

X slope = mass 2 – mass 1 vol 2 – vol 1

D

X