Jove Lab Chem

Simple Distillation — Lab Prep

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.

   • Before you begin, put on a lab coat, splash-proof safety glasses, and nitrile 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    Round-bottom flask

     1    Cork lab ring

     1    Distilling head

     1    Condenser

     1    Connecting tube

     1    10-mL graduated cylinder

     2    1-mL volumetric pipettes

     1    Pipette bulb or controller

     1    Thermometer adapter

     1    Small beaker of sand

     1    Thermometer

     1    Stir bar

     4    Joint clips

     2    Pieces of rubber tubing

     1    Tube of vacuum grease

     2    Stand clamps

   • Set up an example distillation apparatus for the students to refer to. First, place two stands next to each other in the hood and set a stir plate on the base of one of the stands.
   • Place a heating mantle on the stir plate and plug the mantle into a temperature controller. Clamp the round-bottom flask to the stand over the heating mantle.
   • Next, carefully insert the thermometer into the adapter by gently pushing and twisting it through the top. Insert the adapter into the distilling head and adjust the thermometer until the bulb is below the bend. Then, insert the distilling head into the round-bottom flask.
   • Now, clamp the condenser to the second stand, with it oriented diagonally toward the side joint of the distilling head.
   • Connect a piece of rubber tubing to the tap water faucet in the hood and to the inlet port of the condenser, which is the port further from the distilling head.
   • Attach the other tubing to the outlet port, which is the port closer to the distilling head, and place the free end in the drain.
   • Connect the condenser to the distilling head, and then attach the connecting tube to the other end of the condenser.
   • Finally, place a 10-mL graduated cylinder below the connecting tube and secure each joint with a plastic clip.
   • Prepare the two solvents the students will use in the experiment. Each group will need 2 mL of toluene and 2 mL of cyclohexane, so ensure that you have enough for all groups.
   • Pour an appropriate amount of each solvent into a labeled glass bottle, so that the students can measure their solvents without handling any large stock bottles.
   • Set these solvents in the instructor hood for students to access during the experiment.