Dawson Community Fractional Distillatio Weight Data Values Experiment I uploaded for you everything you need. Also, you have to include (Peak area in the results + at least one reference).Let me know if you have any question.There is no conclusion in this lab report Fractional Distillation
Introduction: Distillation is a method by which we can separate and purify liquid components of a
mixture. In some instances, when the difference in boiling points of the components is large, i.e. > 40 °C,
a simple distillation will result in a reasonable separation of the components. When the boiling points
are closer together, a fractional distillation is necessary. A way to visualize what happens when you
distill a two-component mixture is to consider the distillation curve shown below in Figure 1. Let’s
consider a 50:50 mixture of two components, A and B. Let’s say that this mixture boils at a temperature
indicated by T1. At temperature T1 the liquid phase has the composition indicated by point a, that is
50:50 A:B. The arrow that is pointing to the left indicates that the vapor will have the composition
indicated by point b with 82% A and 18% B. This vapor then may condense, on the side of the flask or in
a fractionating column. After condensation occurs this mixture will boil at a lower temperature (T2)
since it is enriched in the lower boiling component. The vapor will have a composition indicated by
point d, that is 95% A and 5% B. Thus, the more times that we can cause vaporization/condensation
events to occur, the purer the material will be when it leaves the distillation apparatus. In fractional
distillation a column with a large surface area is used to allow for multiple vaporization/condensation
events. For this lab, the column is an air condenser packed with steel wool.
Figure 1: Distillation Curve
Gas
b
T1
T2
bp A
100% A
a
Liquid
d
Temperature (°C)
Temperature (°C)
bp B
c
e
95% A
5% B
82% A
18% B
50% A
50% B
100% B
% Composition
The effectiveness of a separation can be determined by gas chromatography (GC). In GC, an inert gas (in
our case helium) is passed over a solid support. How long it takes for a component to pass through the
column, measured in minutes and referred to as the retention time, is impacted by the material’s boiling
point as well as by how well it interacts with the solid support. Since our compounds are all esters and
are therefore similar, the interaction with the solid support should be fairly similar. Thus, the separation
will be mostly impacted by the difference in boiling points, i.e. the compound with the higher boiling
point will be retained for a longer time on the column and will have a longer retention time.
1
Description of the Experiment:
Today we will compare the ability of fractional distillation to separate two different mixtures. One will
contain an equimolar mixture of ethyl acetate and butyl acetate (what is the difference in boiling points
of these two components?) and the other will contain ethyl acetate and propyl acetate (what is the
difference in boiling points for these compounds?). Each pair of students will be assigned a mixture and
will perform a fractional distillation. Each group will obtain data, by GC, on how well they purified their
compound. The data will then be pooled as a class to discover any trends in how well the two mixtures
were separated.
O
O
O
O
ethyl acetate
O
propyl acetate
O
butyl acetate
Check-Out Items:
Fractionating column
10 mL Round bottom Flask
Hickmann still with side arm
Thermometer
Experimental Procedure:
Set up the distillation apparatus
Assemble an apparatus for performing a fractional distillation using a sand bath as your heat source. Use
a clamp to hold the 10 mL round bottom flask on the ring stand. Add a few boiling chips and 5 mL of the
1:1 equimolar solution of the two esters. Place the fractionating column on the round bottom flask.
NOTE: Do NOT twist ground glass joints together as they may get stuck. You just need to place the two
pieces of glassware together!
Stabilize the apparatus by using a second clamp at the top of the fractionating column. Add the Hickmann
still with side arm to the top of the fractioning column.
NOTE: Use your small cap w/hole and a small septum on the side arm. You will remove distillate from
the Hickmann still as the distillation proceeds by removing this cap and using a disposable pipette to
remove the liquid which has collected.
Complete the distillation apparatus by adding a Claisen adapter, thermometer adapter and thermometer.
Make sure that the thermometer extends into the Hickmann still and that the bulb of the thermometer is
directly in the hole above the fractionating column so that you can accurately measure the temperature
of the distillate that you are collecting.
Distillation
Plug in the heating mantle (MAKE SURE that you plug it into the plug in for the rheostat and NOT the
normal outlet). The rheostat will control how much power goes to the heating mantle and thus, how hot
2
it will get. To get a good separation, slowly warm the system up to a gentle reflux. You should observe a
condensation line that moves up the fractionating column and then, eventually, you will see material
begin to collect in the Hickmann still. To get a good measure of the efficiency of your system, collect the
first few drops of distillate and label this will be fraction #1. You should then collect additional material in
approximately 0.5 mL fractions, noting the temperature range of each fraction, until the temperature
drops. Label all fractions. Once the temperature drops, shut off power to the heating mantle and allow
the apparatus to cool before taking apart, cleaning the glassware, and returning the items you checked
out to the stockroom.
Analysis
GC: You will analyze your sample by gas chromatography (GC) using a 30% SE column at a set temperature.
Your TA will show you how to use the GC. You will need to obtain a chromatogram of your first few drops,
of a sample from the middle of your distillation, and of the last sample that you collected.
In order to detect the material that is being separated on the GC, we are using a thermal conductivity
detector. Since different compounds will have different thermal conductivities, we must adjust the data
to reflect the differences in response. We do this by using a response factor:
Compound A Response Factor = peak area for the compound/moles of compound
We have determined these values for you for the three compounds that we are using:
Compound
Ethyl acetate
Response Factor
X
Propyl acetate
Y
Butyl acetate
Z
Mole Fraction:
Determine the mole fraction of the two components in fraction #1, the fraction containing the first few
drops that you distilled using the data above and the data that you obtained from your GC trace.
Lab Results
At the end of the lab, your TA will have you convene as a group to compare your results.
Lab Report
Your lab report should include a copy of all the data that you collected including your GC traces. Discuss
how well your separation occurred compared to the other groups that had the same mixture. If your
separation did not work as well, provide a reasonable rationale for your results.
3
ion
peak area
ethyl acetate
BP: 77.1°C
RE
— # moles (relative) (EA)
(PA)
RE:
1.00
EA
mode fraction=
propyl acetate BP: 102°C
RE: 1.07
x crude weight = x
EA APA
(gram)
mut
ww
e mals
butyl acetate
BP: 126 °C
RF: 1.22
Purchase answer to see full
attachment