Organic Chemistry I Lab
Fractional Distillation of Volatile Organic Solvents
This presentation outlines, in several simple steps,
how to put together a fractional distillation setup
with some helpful hints about the experiment in
general.
1.
Clamp a 250 mL round bottomed flask as
shown in the photo below
(after adding 60 mL of the solvent mixture and a few
boiling chips into the flask
-make sure that you add the solvent mixture into the
flask before you place the flask into the mantle)
At this stage it is useful for you to familiarize yourself with
some of the glassware which you will be using regularly
2.
Place the fractionating column into the
flask
3.
Place the distillation head into the
fractionating column
The next step involves installation of
the thermometer adaptor (with the
thermometer) into the distillation head.
You should install the thermometer into
the adaptor first
4.
Place the thermometer adaptor (with the
thermometer) into the distillation head
note the position of the thermometer bulb
Before continuing with the installation it would be
prudent to place a second clamp around the
fractionating column so that the added weight of the
glassware does not cause the whole setup to tip over.
Do NOT tighten this second clamp.
Glass and metal do not interact
very well!
5.
Install the condenser to the distillation
head. Place a Keck-clip (blue plastic) to
keep the condenser in place
Do NOT let go of the condenser before
fastening it with the Keck-clip
6.
Connect the vacuum adaptor (bent adaptor)
to the cone end of the condenser and secure
it with a Keck clip
Make sure the water inlet hose to the
condenser is the one closer to the “cone” end.
You might wish to attach the hose to the
faucet before installing the condenser
7.
You might wish to clamp (gently) a
graduated cylinder to a second stand so that
you will be able to collect your distillate and
measure the volume of each of your fractions.
This is what the final setup should look like.
(Go to the first slide for an image from further)
Notebook Write-up
Number
your pages
Write using a pen
Give the title of the experiment
Remember this experiment utilizes a “physical method”
The purpose of the experiment is “to separate and
identify volatile organic solvents”
Notebook Write-up
You should have the following sections in your
notebook for this experiment:
Objectives:
Materials:
Hazards:
Procedure:
Data:
Results:
Discussion and Questions:
Notebook Write-up
Materials
You should list all the materials (chemicals) you
are using and also give their structures, i.e.
acetone, cyclohexane, and toluene.
Notebook Write-up
Hazards
You should look up all the possible hazards of
the materials you are using and also comment
how you intend to protect yourself against any of
these (for example, if any of the materials you are
using are skin irritants, you can overcome this
hazard considerably by wearing gloves)
List and discuss only the relevant hazards for you
in the lab
Notebook Write-up
Procedure
Do not copy the procedure from the handout into
your notebook (do not tape the handout into your
notebook either)
Write a brief outline of the procedure. However,
make sure to indicate clearly if you deviate from
what is written in the handout
Notebook Write-up
Data
Write in table form the temperature reading for
each fraction collected. This could be a two or
three column table.
If there are any observations that you wish to
record, you could put an asterisk (or number) in
your table and give further details under the table
(or in the next page)
Notebook Write-up
Results
This is the most important section.
Plot a graph of the data using a graphing software and
attach it to your notebook (see the handout for further
details)
Write in full sentences the interpretation of the graph
clearly. Identify the components in your mixture and the
percentage of each component in the mixture. Mention
any extrapolations you might have carried out.
Notebook Write-up
Discussion and Questions
Feel free to criticize the design of the experiment
here. Mention any sources of error or any errors
you might have inadvertently made (you don’t
have to write anything here if you think all is
well)
Answer the questions assigned.
HAVE FUN