Steam Distillation

Source: Lara Al Hariri at the University of Massachusetts Amherst, MA, USA

1. Preparation of the LaboratoryExpand

   Here, we show the laboratory preparation for 10 students working in pairs, with some excess. Please adjust quantities as needed.

   • To begin, put on the appropriate personal protective equipment, including a lab coat, safety goggles, and gloves.
   • Set out the following glassware and equipment that the students will need to build the distillation apparatus (we suggest that students work in pairs):

     2    Lab stands

     1    Stir plate

     1    Heating mantle

     1    Temperature controller

     1    500-mL round-bottom flask with cork stand

     1    Distilling head

     1    Condenser

     1    Connecting tube

     1    Separatory funnel

     1    Claisen adapter

     1    Thermometer adapter

     1    Thermometer

     1    Small spatula

     1    Stir bar

     4    Joint clips

     2    Pieces of rubber tubing

     1    Tube of vacuum grease

     2    Standard clamps

     1    Ring support

     1    Conical funnel

     1    250-mL round-bottom flask and cork stand

     1    100-mL graduated cylinder

     2    150-mL beakers

     1    125-mL Erlenmeyer flask

     1    Filter paper

     1    500-mL beaker

   • You will need one blender to share between all of the groups. Place it in a central location along with a 10-mL graduated cylinder and a bottle of deionized water.
   • Next, assemble the steam distillation apparatus for the students to refer to during the experiment. First, place the two stands next to each other in the hood.
   • Then, put the stir plate on the base of one of the stands. Set the heating mantle on top of the stir plate and plug it into the temperature controller.
   • Clamp the 500-mL round-bottom flask to the stand above the heating mantle.
   • Locate the Claisen adapter and connect it to the flask.
   • Clamp the condenser to the second stand, orienting it so that it is nearly horizontal.
   • Connect the thermometer adapter to the distilling head and gently insert the thermometer until the bulb is in line with the side arm of the distilling head.
   • Then, add the distilling head into the outer arm of the Claisen adapter and connect the condenser to the distilling head.
   • Attach one piece of rubber tubing to the inlet of the condenser, which is the port furthest away from the distilling head.
   • Attach the other end of the tubing to the tap water faucet in the hood. Connect the second piece of rubber tubing to the other port, which is the outlet, and place the end of the tubing in the drain.
   • Now, get the separatory funnel and make sure that the stopcock is closed. Insert the separatory funnel into the Claisen adapter.
   • Finally, attach the connecting joint to the end of the condenser and attach a 250-mL round-bottom flask to the connecting joint. Secure each joint with a plastic clip.
   • Now that you have set up the demo apparatus, prepare the oranges. Each group will need 3 long peels on a watch glass, so obtain as many oranges and watch glasses as needed.
   • Peel all of the oranges and place 3 peels on each watch glass. Allow the peels to dry for two hours.
   • Next, obtain a bottle of magnesium sulfate and ensure that there is enough for each lab group to have a small spatula full, or about 2 mg each.
   • You will also need a bottle of diethyl ether. Each group will need 40 mL, so ensure that there is enough for the class size.
   • Finally, make sure there is a dedicated container for non-halogenated waste.