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

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.

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

Fermentation and Distillation Procedure Decant the fermentation mixture into a clean 250 mL flask. Setup the distillation apparatus as shown in the photo below. glass tubing should end here Gently boil the solution while collecting the distillate in the test tube. Collect about 6 mL of distillate.

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.

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.

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. slope = DY DX mass2 – mass1 vol2 – vol1