PROCEDURE
1. Assemble the distillation apparatus as shown. Do not begin heating until your instructor has checked your apparatus.
2. Make sure the stopper fitting the probe into the flask and the stopper fitting the flask into the condenser are tightly in place. Connect the two tubes to the condenser inlet/outlet and turn on the cold tap water so that it slowly flows up through the condenser. The third hose goes from the side noozle on the sink to the drain.
NOTE: don’t let hoses spray you or your lab mates.
3. Use a third utility clamp, fitted at the top of the ring stand, to secure the Temperature Probe wire as far as possible from the hot plate.
4. Label the three beakers 1-3. Put beaker #1 in place at the end of the condenser.
5. Plug the temperature probe into Channel 1 on the LogPro interface. Next, plug the LabPro in to an outlet, You ill hear beeps and see lights. Finally, ensure a USB cable is connecting the laptop to the LogPro.
6. Turn on laptop, press enter when the password box appears. Start the LoggerPro program, found on the desktop.
7. Press the folder button, open the Chemistry_with_computers folder and choose the “Fractional Distillation” file.
8. Use a graduated cylinder to obtain 60 mL of ethanol. Using a funnel, pour the ethanol into the flask. Using a funnel, pour 60 mL of deionized water into the same flask. Add 3 or 4 boiling chips to the flask.
9. Have your instructor check your set-up, and then turn the hot plate on to its maximum setting and hit the collect button.
10. When 30 mL of liquid (distillate) have been collected in beaker #1, remove it and insert beaker #2 in its place. This 30-mL portion is called Fraction 1. Set it aside.
11. After you have collected 30 mL of Fraction 2 in beaker #2, quickly replace it with beaker #3. Set Fraction 2 aside.
12. After you have collected 30 mL of Fraction 3 in beaker #3, turn off the hot plate. Set Fraction 3 aside and press the stop button.
13. Determine and record the mass of a clean, dry graduated cylinder, the smallest you can find that will contain all of your fluid. Pour the contents of Fraction 1 into the graduated cylinder. Read and record its volume, to the nearest 0.1 mL. Then determine and record the mass of the distillate plus the graduated cylinder.
14. Discard Fraction 1 as directed by your instructor. Pour the contents of Fraction 2 into a graduated cylinder. Read and record its volume, to the nearest 0.1 mL. Then determine and record the mass of the distillate plus the graduated cylinder.
15. Repeat this last step for Fraction 3.
16. On the laptop, move your mouse over the displayed graph. Find the initial boiling temperature of the mixture (the point where the rapidly rising initial temperature ends, and the slow increase in temperature begins). Record this value (round to the nearest 0.1°C) in your data table.
17. Print a copy of the graph. Using your printed graph, locate and label the initial boiling temperature you obtained in the previous.