University of Mary Washington Distillation and Gas Chromatography Lab Report


The temperature that has been recorded for the five fractions: You are supposed to make a graph for it
like the one below:
Background reading / material
This is a very important organic chemistry technique. Please read the following sections of

Chapter 12,sections 12.1-12.3a, 12.4, 12.5, 12.8
Furthermore, this lab will require an understanding of boiling points and intermolecular forces,
discussed in Chapter 1 of Klein.
The distillation mixture is composed of somewhat toxic and very flammable substances.
Handle the mixture in the hood and avoid breathing its vapors. Do not use gloves while setting
up the glassware; it is not toxic, and wearing gloves makes it easier to drop the glassware. It
is probably not necessary to wear gloves at all in this experiment. If you get the distillation
mixture on your hands, wash it off with cold water and soap.
Make sure the heating mantle is plugged into the controller in the hood. NEVER plug the
heating mantle directly into a regular receptacle, and NEVER turn on the hot plate while
the heating mantle is setting on it. Do not heat the distillation flask to dryness; the flask
1) Place 22 mL of the provided distillation mixture into a 50 mL round-bottom flask and add a
few boiling stones. Reserve about 0.5-1 mL (about 10 -20 drops) for GC and IR. Grease
the joint between the round bottom flask and the Vigreux column – use the grease
2) Distilling flask – Choose the flask based on the volume of distilland. Too large a flask will
result in the loss of product because of liquid left behind on the walls of the flask. If the
flask is too small, the liquid may bump and boil over into the condenser and contaminate
the distillate. The boiling flask should be 1/3 to 2/3 full of distilland with a few boiling chips
(boileezers) added to prevent bumping. Add the boiling chips to the flask before you
assemble the apparatus; never add a boiling stone to a hot liquid.
3) Using the diagrams in chapter 12 in Techniques in Organic Chemistry as guides (especially
12.17), clamp the flask to a fractional distillation apparatus. Pick up a Vigreux distilling
column from the back counter. Use a 10 mL graduated cylinder in place of the usual
receiving flask so you can monitor the volume of distillate during the distillation. Keck clips
(figure 6) may be used to secure the joints on either end of the condenser (these are
available on the back counter); do not use a Keck clip on the distilling flask because it may
4) Clamp the glassware securely as shown in Figure 12.17 of Techniques in Organic
Chemistry. Be careful, glassware is expensive. Make sure all joints are tight and there
are no leaks. Blue Keck clips (figure 1) may be used to keep the joints tight, but they are
NOT substitutes for clamps.
Figure 1 – Keck Clips and Placement of Keck Clips over glassware joints.
5) For proper heat transfer, adjust the heating mantle so it touches the bottom of the distilling
6) Obtain a 200°C thermometer from the back counter. When inserting the thermometer into
the distillation head, make sure it is centered – not closer to one wall or the other. The bulb
of the thermometer should be below the bottom of the sidearm where it will be moistened
by the condensing vapors of the distillate and give the correct distillation temperature. See
figure 2 for thermometer placement.
Figure 2 – Correct Placement of Thermometer in Distillation Head
7) Attach the condenser tubing to the condenser, hook up the lower end to the water supply,
and set the upper end into the drain.
8) All joints should be tight, and the apparatus should be securely clamped. Your apparatus
should look like the set-up in Figure 3 except you will not be using the thermometer probe:
Figure 3 – Fractional distillation set-up (adapted from Vernier Software and Technology)
9) Before you turn on the heat for your distillation, have the instructor or lab-aide check
the set-up.
10) Turn on the condenser water to a slow stream, and set the heat controller to a medium high
11) Heat the flask until the liquid begins to boil. Adjust the controller to distill the liquid at a rate
of about 2 mL/min (2 drops every 3 seconds). As needed turn the heat up to maintain the
distillation rate. While the sample is heating, you may be able to inject your first sample
into the Vernier Mini GC or obtain an IR (see the data analysis sample). Make sure that
you do not lose focus on the distillation as once it starts to boil you will need to focus on
collecting the temperature data and fractions.
12) Record the initial temperature when the first drops of distillate fall into the graduated
cylinder, and record the temperature after every 1 mL of distillate is collected.
13) Once you collect about 1 mL, quickly transfer the sample to a clean dry test tube and
replace the graduated cylinder to continue to collect distillate. The sample in the test tube
is fraction #1.
14) Continue to collect the distillate and record the temperature every 1 mL. After collecting the
next 2 mL, quickly transfer this fraction to another clean dry test tube and replace the
graduated cylinder to continue to collect the distillate. The sample in the second test tube
is fraction #2.
15) Continue to collect the distillate and record the temperature every 1 mL. After collecting the
next 4 mL, quickly transfer this fraction to another clean dry test tube and replace the
graduated cylinder to continue to collect the distillate. The sample in the third test tube is
fraction #3.
16) Continue to collect the distillate and record the temperature every 1 mL. After collecting the
next 4 mL, quickly transfer this fraction to another clean dry test tube and replace the
graduated cylinder to continue to collect the distillate. The sample in the fourth test tube is
fraction #4.
17) Continue to collect the distillate and record the temperature every 1 mL. After collecting the
next 2 mL, quickly transfer this fraction to another clean dry test tube and replace the
graduated cylinder to continue to collect the distillate. The sample in the fifth test tube is
fraction #5. Turn off the heat and if possible carefully drop the heating mantle to ensure
that the round bottom distilling flask does not go dry. Never heat a distilling flask to
dryness. At best, the flask could be difficult to clean after the distillation, and, at worst,
there could be an explosion due to residues from the solution.
Summary of the fractions to be collected:
Fraction #1
1 mL
Fraction #2
2 mL
Fraction #3
4 mL
Fraction #4
4 mL
Fraction #5
3 mL
18) Lower the heating mantle from the flask, and allow the apparatus to cool. Dispose of the
distillate in the USED Non-halogenated Solvent bottle.
19) Obtain an IR spectrum of fraction 1, fraction 5, and the original mixture. The original mixture
and possibly fraction 5 can be analyzed after lab. Fraction 1 will evaporate quickly.
Analysis of Samples – GC (Copied from Vernier Lab Manual)
 LabQuest
 Vernier Mini GC
 1 μL glass microsyringe
 Vial of acetone for cleaning
You will need to analyze the reserved initial mixture and each distillation fraction collected
(fraction #1 – #5) using the Vernier Mini GC.
1) Prepare the Vernier Mini GC for data collection.
a. Turn on the Mini GC.
b. Connect the USB cable of the Mini GC to the USB port on LabQuest.
c. Start the data-collection program, and then choose New from the File menu.
d. Click Collect in Logger Pro, or tap ► in LabQuest, to bring up the Temperature-Pressure
e. Set the Temperature-Pressure values according to the settings listed for Run 1 on the
next page:
Set the Temperature-Pressure values to:
Start temperature
Hold time
Ramp rate
Final temperature
Hold time
Total length
40 °C
1 min
5 min
8.5 min
5.0 kPa
2) Select Done to initiate the Mini GC warm up. Note: A new message will appear, “Do not
inject until GC is ready”, and the LED on the Mini GC is red. The Mini GC will take a few
minutes to warm up and stabilize. When the Mini GC is ready for injection, the message will
read, “Inject and select Collect simultaneously”, and the LED will turn to green. Continue
with Step 2 during warm up.
3) Follow the steps below to clean and flush the syringe with acetone. Important: The glass
syringe is fragile. Be careful not to bend the needle or bend the plunger. Never pull the
plunger back more than 50% of its total volume. Be careful not to bend the plunger as you
press it down.
a. Depress the plunger fully.
b. Submerge the tip of the syringe needle into the vial of acetone.
c. Pull back the plunger to fill the barrel about 1/3 full of acetone. Examine the barrel of the
syringe and estimate the amount of acetone in the barrel.
d. Expel the liquid onto a Kimwipe or a paper towel.
e. Repeat Steps a–d at least two times, until you are comfortable pulling up a liquid into the
syringe and measuring the volume in the syringe barrel. Use a Kimwipe or a paper towel
to carefully pat around the tip of the syringe needle.
4) Follow the process in Step 3 to clean and flush the syringe with Solution 1.
5) Collect a volume of the mixture for injection.
a. Submerge the needle into the vial of Solution 1
one last time.
b. Draw up approximately 0.1 L of liquid. It is not
critical that the volume be exactly 0.1 L; a tiny
bit more or less is all right (see Figure 2 for an
example 0f 0.2 L).
c. After collecting your sample, gently wipe the
needle from, barrel to tip, with a Kimwipe.
Figure 2
6) Prepare for injection and the start of data collection. When the Mini GC has reached the
correct start temperature and pressure, the message reads, “Inject and select Collect
simultaneously”, and the LED on the Mini GC is green.
a. To insert the needle of the syringe into the injection port of the Mini GC, hold the syringe
with one hand and steady the needle with your other
hand. Insert the needle into the injection port until the
needle stop is fully seated. Do not force the needle into
the injection port. If the needle sticks, rotate it slightly
while inserting. Do not move the plunger yet (see Figure
b. Simultaneously, depress the syringe plunger and select
Collect to begin data collection. Pull the needle out of the
injection port immediately.
7) While the data collection proceeds, repeat Step 2 to
thoroughly clean the syringe and needle. It may take more
than three flushes to feel the syringe plunger move smoothly
again, which is your indicator that the syringe and needle are
both suitably clean.
Figure 3
Data collection will end after 8.5 minutes. You may stop the run
before 5 minutes if two peaks appear and the trace returns to
8) Analyze your chromatogram using Peak Integration. Record retention times and peak
areas for each peak in your notebook. Note if the fractional distillation was carried out
correctly, some fractions should have only one peak.
Possible unknowns
b.p. (oC)
Ethyl Acetate
Ethyl Butyrate
1. Complete the following table with data from your lab notebook
Peak 1
Peak 1 %
Peak 2
Peak 2 %
Initial mixture
Fraction 1
Fraction 3
Fraction 5
2. Attach the plot of temperature versus volume collected after this page. DO NOT CONNECT
THE DOTS! It is permissible to make a smooth curve through the points.
3. What are the boiling points of the two components, based off of your results? Label these
points on your graph.
4. What are the components of the mixture? Use evidence from both the distillation and the IR
5. Describe the efficiency of your separation, using any appropriate data from the distillation,
IR, and/or GC.

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