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1. CHM142L Organic Chemistry 1 Laboratory
3rd
Quarter SY 2014-2015
Simple and Steam Distillation
Miranda, Marilyn1
, Ayson, Jose Paolo, L2
1
Professor, School of Chemical Engineering, Chemistry and Biotechnology, Mapua Institute of Technology; 2
Student (s),CH142L/A31, School of Chemical Engineering,
Chemistry and Biotechnology, Mapua Institute of Technology
ABSTRACT
The objectives of this experiment are to assemble a simple and a steam distillation set-up, to identify and recognize the
significance of all parts of the set-up, and to purify a sample using simple and steam distillation. Distillation is the separation
of two or more liquids of different volatility. In simple distillation, a liquid is boiled and the vapours work through the apparatus
until they reach the condenser where they are cooled and reliquify. Steam distillation is used for separating substances which
are immiscible with water, volatile in steam & having high vapour pressure at the boiling temperature of water. Simple
distillation of toluene was performed in this experiment having 32.32 % of percentage recovery and steam distillation of p-
dichlorobenzene was also performed and obtained 89% of percentage recovery. In boiling which a solvent becomes
superheated and then undergoes a sudden release of a large vapour bubble, explosively forcing liquid outside of a flask is
called bumping. To prevent this from happening we add glass beads in the distilling flask. Glass beads provide nucleation
sites; extremely localized budding for gaseous bubbles, so the liquid boils smoothly or more easily. Materials and procedures
on hoe to perform the experiment is mention in here, like the quick fit equipment was mostly used in this experiment having
one-necked pear-shaped flask, two-necked pear-shaped flask and the distillation set-up. Theories and relationships about
distillation, boiling point and volatility was learned and observed in this experiment.
Keywords: albumin, casein, invertase, Bradford Assay, Warburg-Christian Assay, Benedict’s reagent
INTRODUCTION
The purpose of the experiment is to show to students
how simple and steam distillations are being
accomplished. To show us how to assemble a simple and
a steam distillation set –up and identify ad recognize the
significance of all parts of the set-up. Also, learn the
techniques in purifying samples using these 2 methods.
According to the organic chemistry laboratory manual,
the volatility of a compound is based on the equilibrium
vapour pressure exerted by the compound at a particular
temperature. Different compounds will exert different
vapour pressures at a given temperature because of
variations in the intermolecular forces of attraction
working these different compounds. Compounds that
have stronger intermolecular forces will be harder to
detach from each other, hence lesser volatility.
Compounds that are more volatile will change faster in to
vapour than does that have low volatilities. The object of
distillation is the separation of a volatile liquid from a non-
volatile substance or, more frequently, the separation of
two or more liquids of different volatility.
According to Sydney Young, the difficulty of separating
the components of a mixture diminishes as the difference
between their boiling points increases. One must
consider the relation between the boiling points, or the
vapour pressures, of mixtures of the substances and their
composition. Simple and fractional distillations are
carried out on miscible mixtures. Ideal mixtures follow
Raoult's law: The total vapour pressure of the system is
determined by adding together the products of the vapour
pressure and the respective mole fraction of each
compound. Distillation can also be performed on mixtures
in which the two compounds are not miscible. This
process is called codistillation. When one of the
compounds is water, the process is called steam
distillation. When two immiscible liquids are distilled, the
total vapour pressure above the liquid is equal to the sum
of the vapour pressures of each compound, this
relationship known as Dalton's law.
MATERIALS AND METHODS
In simple distillation, we used some of the apparatus in
the Quick fit like one-necked pear-shaped flask for the
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2. CHM142L Organic Chemistry 1 Laboratory
3rd
Quarter SY 2014-2015
mixture to be distilled or the distilland, still head for
holding the thermometer in place and the connector to
the condenser. We assembled the set-up as shown in
figure 1 but with some modifications since we used pear-
shaped flask as the container for the distilland and the
still head as the connector and holder.
FIGURE 1
The distilland we collected was 15 ml of toluene. We
started the distillation beginning with switching the heat
regulator to number 6. Once the collected distillate
reached 1ml the temperature was read and recorded. We
record all the different temperatures as the volume of the
distillate increases. After collecting data, we plot the
temperature against the volume of the distillate collected
and recorded the temperature range at which most the
liquid distils.
For the steam distillation, quick fit equipment was also
used in this distillation. Two-necked pear-shaped flask
was used for the distilland so that the steam or vapour
will pass through to first neck and the second for the
vapour which contains the distillate. We assembled the
set-up liked the set-up in figure 2 with some modifications
since we used the 2 necked pear-shaped flask for the
distilland than an Erlenmeyer flask and hotplate for the
source of heat. Also, we placed safety tube in the steam
generator. We gathered 2 grams of impure p-
dichlorobenzene and dissolved it in a 5ml of distilled
water. When the set-up was ready, we begun the
distillation by transferring the distilland in the pear-shaped
flask and connected the steam tube making sure that the
steam will touch the contents at the bottom of the flask.
We heat the steam generator and proceeded with the
distillation. After 10-15 minutes, most of the p-
dichlorobenzene has been distilled. We heat the
condenser with a Bunsen burner since it was clogged.
After collecting the distillate, we filter the p-
dichlorobenzene with a vacuum filtration set-up and were
air dried. We measured the mass of the pure substance
and obtain its melting point using the Thomas Hoover
apparatus. The percentage recovery was computed using
the obtained data in the experiment.
FIGURE 2
DISCUSSION AND RESULTS
I. Simple Distillation
Graph 1: Volume of the distillate vs. Temperature
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3. CHM142L Organic Chemistry 1 Laboratory
3rd
Quarter SY 2014-2015
Table 1: Simple Distillation Data
Boiling point of the sample
(◦c)
100 – 110
Total volume collected(ml) 13
Percentage recovery 32.31%
The boiling point range we got has a large difference; this
must be because of our lack of precision and accuracy in
reading the temperature and volume. I presume that the
boiling point range must be at 106 ˚C to 110 ˚C, since the
true value of the boiling point of toluene is 110˚C. We
have a 32.31% recovery meaning most of our collected
distillate is not as pure as the pure substance maybe
because some of the impure substance was transferred
with the distillate in the distillation because of the close
boiling point of both of the substance. In simple
distillation, a mixture of liquids is heated to the
temperature at which one of its components will boil, and
then the vapour from the hot mixture is collected and
condensed into liquid, but there are many kinds of
mixtures that cannot be separated this way and require a
more advanced approach. Since the mixture in simple
distillation is only boiled and condensed once, the final
composition of the product will match the composition of
the vapour, which means it may contain significant
impurities. The closer the boiling points of the liquids in
the mixture, the more impure the final product will be.
Consequently, simple distillation is typically used only if
the boiling points of the mixture's components are
separated by at least 25 degrees Celsius. But simple
distillation uses less energy. This is because it uses
simple apparatus which consists of only a distilling pot
and a condenser, an adapter and a receiver. Due to the
simple equipment used, the ways through which much
energy can be used or lost during the separation process
are minimized thus making the process more energy
efficient. Also, simple distillation process requires only
one cycle in order to obtain the required product. When
separating a simple solution, provided the compounds
making up the mixture have a great gap in their boiling
points, there is usually no need for continuous distillation
which most of the time consumes a lot of time and
energy. With simple distillation, a clean final product can
be achieved using a single process only.
Table 2: Simple Distillation Observations
OBSERVATIONS
 It took a very long time to have a distillate.
 After a few minutes, the temperature increases.
 The temperature remained at 110˚C and the
distillate continuously flowed in the graduated
cylinder.
 At 110˚C, the total volume is 13 ml.
In boiling which a solvent becomes superheated and then
undergoes a sudden release of a large vapour bubble,
explosively forcing liquid outside of a flask is called
bumping. To prevent this from happening we add glass
beads in the distilling flask. Glass beads provide
nucleation sites; extremely localized budding for gaseous
bubbles, so the liquid boils smoothly or more easily. The
air bubbles break the surface tension of the liquid being
heated and prevent superheating and bumping. Glass
beads should not be added to liquid that is already near
its boiling point, because it can cause to solvent to boil
over violently that causes product loss, hence it must be
add before distillation. It is necessary to control the heat
rate to prevent the continuous flow of distillate that may
contain impurities, therefor when the heat is controlled
the ways of the impurities to evaporate is lesser since it
may not reach its boiling point.
II. Steam Distillation
Table 3: Steam Distillation Data
Melting point of crude
sample
56-58 ˚C
Melting point of purified
sample
49-51˚C
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4. CHM142L Organic Chemistry 1 Laboratory
3rd
Quarter SY 2014-2015
Weight of crude sample 2.0 g
Weight of purified sample 1.78 g
Percentage recovery 89 %
The percentage recovery we got is better than the simple
distillation since we properly followed the instruction that
the steam or vapour must touch the contents at the
bottom of the flask since it is the substance we want to
collect. Steam distillation is useful for extracting most
fats, oils and waxes. This process works well for types of
substances that do not mix with water, which are known
as immiscible substances. Also, because the steam
temperature can remain at the boiling point of water, this
process also has a cost benefit of requiring less fuel for
the steam boiler. However, at high distillation
temperatures volatile substances undergo denaturation,
process in which proteins or nucleic acids lose the
quaternary structure, tertiary structure and secondary
structure which is present in their native state, and some
valuable components get modified. Steam distillation is
best suited in substances that do not mixed with each
other, which are known as immiscible substances.
Table 4: Steam Distillation Observations
OBSERVATION
 The crude p-dichlorobenzene was dissolved in
water wherein there were red-orange and white
colors.
 The red-orange solution was on the top and the
white portion is at the bottom.
 The white part of the solution started to
vaporized and condensed by the condenser as
the distillation continues.
 In the inner wall of the condenser, white solids
are formed.
 The solution crystallized in the cooling bath.
Safety tube is needed to release the excess steam and
pressure, preventing an explosion. It also allow the water
to escape when the pressure get higher. Since steam
distillation is a distillation process, the steam generator
and sample flask must have glass beads to prevent
superheating and bumping. Heat must be applied to the
steam generator and the sample flask to produce steam
and to make the sample boil and produce vapour. The
condenser must always be filled with fresh water during
the entire process because anytime or at any moment the
vapour containing the desired substance will pass
through the condenser. It should be cold because its low
temperature will make the vapour travelling through the
condenser turn to its liquid form. The compound being
steam distilled must not have any reaction with water
because it might cause impurities.
CONCLUSION
The objectives of this experiment are to assemble a
simple and a steam distillation set-up, to identify and
recognize the significance of all parts of the set-up, and
to purify a sample using simple and steam distillation.
These objectives were achieved since we have
assembled both distillation set-up and purified impure
sample using the two methods. I realized that simple
distillation is much easier to perform but greater chance
of having impure product while steam distillation is best
performed in substances that are immiscible like water
and oil. In distillation, never forget to add glass beads or
boiling chips before proceeding to distillation since it will
affect the result badly. Generally, distillation is the
separation of substance using their difference in volatility.
These methods will be useful for us chemical engineering
students in the future who will take the path of the
industry that apply these methods of separation and
purification.
REFERENCES
Anonymous. (n.d.). Organic Chemistry Lab 1
Experiment Packet Fall Quarter 07 .
Retrieved March 5, 2015, from
seattlecentral:
http://www.seattlecentral.edu/faculty/ptr
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5. CHM142L Organic Chemistry 1 Laboratory
3rd
Quarter SY 2014-2015
an/bastyr/summer%2007/organic
%20lecture/Lab%20Packetfall07.pdf
Baluyot, J. Y., & De Castro, K. A. (n.d.).
Organic Chemistry Laboratory Manual
for Chemical Engineering Students.
Klein, D. (2012). Organic Chemsitry.
Massachusetts: John Wiley & Sons, Inc.
Young, S. (1922). Distillation Principles and
Processes. London: Macmillan and Co.,
Limited.
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