Fractional and Simple Distillation - Lab Experiment | CHEM 2050, Lab Reports of Organic Chemistry

Download Fractional and Simple Distillation - Lab Experiment | CHEM 2050 and more Lab Reports Organic Chemistry in PDF only on Docsity! Experiment 4: FRACTIONAL AND SIMPLE DISTILLATION From: http://www.chemistry.mcmaster.ca/~chem2o6/labmanual/expt3/exp3-p.html Experimental Notes and Warnings 1 Exercise care when you put in your thermometer into the thermometer adapter i) Hold the thermometer adapter as well as the thermometer using paper towels. Hold the adapter with your fingers. DO NOT PRESS INTO THE PALM OF YOUR HAND. ii) Slide the rubber stopper containing the thermometer with an even pressure on top of the glass adapter. If any rubber tubing, corks or stoppers which have become hardened after excessive use, simply cut the rubber or cork from the glass. 2. The water flow through the condenser should not be with high force! 3. Don’t let all the solvents in the distillation flask (RB-flask) go completely dry. 4. The heating mantle needs to be plugged into a transformer. Part A. Simple Distillation PROCEDURE Assemble the simple distillation apparatus shown below. Use a 100 ml graduated cylinder as you receiving vial. Make sure that the mouth of the grad-cylinder is placed into the mouth of the adaptor/ vacuum-adaptor. Add 25mL of cyclohexane and 25mL of toluene to the round bottom flask, and a couple of boiling chips/boileezers. The thermometer bulb needs to be placed right below the side arm of the distill head. Make sure that ring stand is ~ 10cm above the bench- surface of you. This is done to ensure that you can lower the heating in case of over boiling of the liquid mixture. The distillation apparatus should not be completely closed (ie. There should be some space at the mouth of the vacuum adaptor to vent excess pressure). Heating Mantle H2O in H2O out Round Bottom Flask/ Distilling Flask/ RB flask Thermometer Thermometer Adaptor Distill head/ still head Condensor Adaptor/ Vacuum Adaptor Receiver/ receiving vial/ Receiving container Simple Distillation apparatus Connect the mantle to the transformer (After making sure all connections are tight, heat the flask until boiling starts, and the transformer setting initially should be ~3.5. Record the temperature 1 every 2 mL as the distillation proceeds till you collect 44-45 mL of distillate. Once ~24-25ml of distillate is collected; increase the transformer setting to 4.5-5. Boileezers/ boiling-chips are used to prevent uneven boiling and prevents "bumping" These are white in color and inert. They contain small pores which has air trapped in. During boiling the air trapped inside the pores escape as small bubbles. Part B. Fractional Distillation PROCEDURE Assemble the apparatus shown above. Use a 100 ml graduated cylinder as you receiving vial. Make sure that the mouth of the grad-cylinder is placed into the mouth of the adaptor/ vacuum- adaptor. Add 25mL of cyclohexane and 25mL of toluene to the round bottom flask, and a couple of boiling chips/boileezers. The thermometer bulb needs to be placed right below the side arm of the distill head. Make sure that ring stand is ~ 10cm above the bench-surface of you. This is done to ensure that you can lower the heating in case of over boiling of the liquid mixture. The distillation apparatus should not be completely closed (ie. There should be some space at the mouth of the vacuum adaptor to vent excess pressure). Connect the mantle to the transformer (After making sure all connections are tight, heat the flask until boiling starts, and the transformer setting initially should be ~4.5. Record the temperature every 2 mL as the 2 Thermometer Distill head Round bottom Flask Distilling column filled with steel wool