A.
SIMPLE DISTILLATION (student 1)
Procedure: Set up a simple distillation apparatus, such as that shown in the laboratory, with a 100-mL flask containing 40-mL of a binary mixture provided by your instructor. Heat with a heating mantle and collect the distillate in a 100-mL graduated cylinder at the rate of about 2-mL per minute. Record the initial boiling point and the boiling point after each 2-mL of distillate is obtained. Also collect at least three fractions (5-10 drops per fraction) at intervals indicated by your instructor and store in a vial obtained from your instructor. Screw the cap on vial tightly and make sure to properly label your vials for later use in chromatographic analysis.
B.
FRACTIONAL DISTILLATION (student 2: unpacked column)
Procedure: Set up a fractional distillation apparatus, such as that shown in the laboratory, with a 100-mL flask containing 40-mL of a binary mixture provided by your instructor. Heat with a heating mantle and collect the distillate in a 100-mL graduated cylinder at the rate of about 2-mL per minute. Distill and record boiling points vs. distillate volumes as described in procedure A. Also collect three fractions as described in procedure A.
C.
FRACTIONAL DISTILLATION (student 3: packed column)
Procedure: Follow procedure B except use a packed column. Be careful not to turn the columns upside down.
D.
GC Analysis (for all students)
Determine the relative amount of each component in each fraction by means of gas chromatography. Consult your instructor for the operating procedures.
Remember to write down all pertinent information about the specific GC instrument you are using – use the same instrument as your partners.
E.
Graph (for all students)
Plot the boiling point (ordinate) vs. distillate volume (abscissa) for all distillations on the same graph. Include this graph in your report with the boiling points and compositions of the fractions analyzed. Indicate on your graphs the points at which these fractions were collected.
Distillation and Gas Chromatography Page 1