2. ATOMIC ENERGY CENTRAL SCHOOL
OSCOM
DEPARTMENT OF CHEMISTRY
CERTIFICATE
This is to certify that SWAROOP SUNDAR PUHAN, a
student of class XII has successfully completed the
research on the below mentioned project under the
guidance of MR.M.K.SONI ( Subject Teacher ) during
the year 2014-15 in partial fulfillment of chemistry
practical examination conducted by AISSCE, New Delhi.
Signature of Signature of
external examiner Chemistry Teacher
3. ACKNOWLEDGEMENT
In the accomplishment of this project successfully,
many people have best owned upon me their
blessings and the heart pledged support, this time I
am utilizing to thank all the people who have been
concerned with project.
Primarily I would thank god for being able to complete
this project with success. Then I would like to thank
my principal Mr.A.K.Singh and chemistry teacher
Mr.M.K.Soni, whose valuable guidance has been the
ones that helped me patch this project and make it
full proof success.His suggestions and his instructions
have served as the major contributor towards the
completion of the project.
Then I would like to thank my parents and friends
who have helped me with their valuable suggestions
and guidance has been helpful in various phases of
the completion of the project.
Last but not the least I would like to thank my
classmates who have helped me a lot and also Sir
Lab attendant Mr.Laxmi Narayana.
4. DECLARATION
I hereby declare that project work entitled “PREPARATION
OF SOAP & DETERMINING FOAMING CAPACITY OF
DIFFERENT SOAPS”, submitted to the department of
Chemistry, Atomic Energy Central School (OSCOM) for the
subject Chemistry under the guidance of Mr.M.K.Soni is a
record of original work done by me. I further declare that this
project or any part of it has not been submitted elsewhere for
any other class.
CLASS: XII
PLACE: ATOMIC ENERGY CENTRAL SCHOOL, OSCOM
DATE:
6. PREPARATION OF SOAP
GENERAL INFORMATION
What Are Oils & Fats?
Alcohol or alkanols may be considered as hydroxyl derivatives of saturated
hydrocarbons or alkanes and represented by general formula R-OH group.
All alcohols contain the hydroxyl group (-OH) as the functional group, which
determine the general properties of the family. The remaining part, i.e., other than the
(–OH) group is called the hydrocarbon structure.
Alcohols are classified as mono, di- and trihydric alcohols according to the
number of hydroxyl groups contained in their molecules. Thus:
C2H5OH CH2OH C2H4(OH)2
Ethyl Alcohol │ OR
(Monohydric) CH2OH
Glycol (Dihydric)
CH2OH
│
CH2OH OR C3H5(OH)3
│
CH2OH
Glycerol (Trihydric)
Glycerol is a trihydric alcohol with three hydroxyl groups.
Carboxylic (or alkanoic) acids are the organic compounds containing carboxyl
(–COOH) group. They are represented by the general formula R–COOH.
7. Aliphatic monocarboxylic acids (containing one carboxyl group) are known as
fatty acids because some of their higher members with long hydrocarbon chains are
obtained from oils and fats. Members of family of carboxylic acids in which R
contains 15 or more carbon atoms are known as higher fatty acids. Some common
higher fatty acids are:
C15H31COOH C17H35COOH C17H35COOH
(Palmitic acid) (Oleic acid) (Stearic acid)
Oils and fats are the triesters of glycerol with various long chain organic acids,
both saturated and unsaturated.
These triesters are usually known as glycerides.
Oils are liquids at ordinary temperatures while fats are solids.
The glycerides constituting oils contain a larger proportion of unsaturated
acids, such as oleic acid (C17H33COOH), linoleic acid (C17H31COOH), etc., while the
glycerides forming the fats contain a larger proportion of saturated acids, such as
lauric acid (C11H23COOH), myristic acid (C13H27COOH), palmitic acid
(C15H31COOH) and stearic acid (C17H35COOH).
The glycerides are named according to the acid radical present in them. For
instance, the glyceride containing stearic acid radical is called stearin or tristearin and
the one containing the palmitic acid radical is named as palmitin or tripalmitin.
CH2OOCC17H35 CH2OOCC15H31
│ │
CHOOCC17H35 CHOOCC15H31
│ │
CH2OOCC17H35 CH2OOCC15H31
(Stearin or triesterin) (Palmitin or tripalmitin)
8. Usually more than one acid radical is present in the same glyceride. These are called
mixed glycerides. The naturally occurring oils and fats are generally mixtures of such
‘mixed glycerides’.
For instance:
CH2OOCC17H35 CH2OOCC15H31
│ │
CHOOCC15H31 CHOOCC17H35
│ │
CH2OOCC17H35 CH2OOCC17H35
(Oleo-palmito-stearin) (Palmito-distearin)
CH2OOCC17H35
│
CHOOCC15H31
│
CH2OOCC15H31
(Stearo-dipalmitin)
WHAT ARE SOAPS?
Soaps are mixtures of sodium or potassium salts of higher fatty acids such as
stearic acid, palmitic acid, oleic acid. They are usually obtained by the hydrolysis of
oils and fats with sodium or potassium hydroxide (alkali hydrolysis).
9. For example,
CH2OOCC15H31 CH2OH 2C15H31COONa
│ │ (Sodium palmitate)
CHOOCC15H31 + NaOH → CHOH (Soap)
│ │
CH2OOCC17H35 CH2OH C17H35COONa
(Dipalmito-stearin) (Sodium Sterate)
(Oil or fat) (Soap)
The alkali hydrolysis of oil and fat is known as Saponification.
The sodium soaps are generally hard in consistency and are known as Hard
Soaps. The potassium soaps, on the other hand, are comparatively soft and more
soluble and are referred to as Soft Soaps. Shaving creams, vanishing creams,
shampoos, etc., are all potassium soaps
CLEANSING ACTION OF SOAPS:
Soaps act as cleansing agent by decreasing the surface tension of water. Any
surface or interface has a surface tension, or surface energy caused by the unequal
attraction, between molecules in opposite sides. A detergent (cleansing agent) ties
together the two surfaces and consequently diminishes the fraction of dissimilar
cohesive forces at the surface and hence decreases the surface energy. The adsorption
of the detergent at the solid surface permits wetting of the surface by water and rolling
up of oil films into small droplets.
Cleansing (or washing) properties of soaps and detergents depend on the lowering
they cause in the surface tension of water. Greater the lowering in the value of
surface tension, greater will be the cleansing capacity of the detergent.
10. Surface tension of two soap solutions ( 𝛾1and 𝛾2) can be easily compared by
counting the number of drops ( 𝑛1and 𝑛2) formed from equal volumes containing equal
weights of the detergents.
𝛾1/ 𝛾2 = 𝑛1/ 𝑛2
Stalagmometer or Drop pipette:
It is an apparatus used for comparing relative surface tension of liquids. It
consists of a capillary tube the end of which is flattened out (in order to give a large
dropping surface) and the surface is ground flat and polished. The capillary is sealed
on to a tube of wider bore on which a bulb is blown and on the stem of the tube, two
marks are etched, one above and another below the bulb.
EXPERIMENT:-
OBJECTIVE:
a) To prepare soap from oils (say Mahuwa oil, ground nut oil and coconut oil).
b) To compare the soap prepared with the market soap by determining their
foaming capacity and cleaning effect.
APPARATUS:
Beakers, Stalagmometer (drop pipette), test tubes, petri dishes, stop watch.
CHEMICALS REQUIRED:
The washing soap is prepared from the following chemicals:
1. Mahuwa Oil = 100g
2. Caustic Soda = 25g
3. Starch = 25g
4. Water = 150ml
11. PROCEDURES:
1. Dissolve caustic soda in 150ml of water. This solution is called lye. Let this
soda lye cool.
2. Warm the oil on flame and mix 50g of starch with it. Remove the flame and
allow the oil to cool.
3. When the oil and soda lye are at about the same temperature (which can be
tested by putting a finger in each of them at the same time). Add soda lye to
the oil in a thin stream.
4. Stir the mass constantly well with a wooden rod till the whole lye has been
added. A creamy pasty mass is obtained.
5. Stir the mass more till a semi-solid mass is obtained. Transfer it into an iron
mould or a wooden frame.
6. Cover the mould or frame with wooden board or a gunny bag and leave it for
few hours.
7. Remove the flame and take out the soda slab. Cut it with the help of a wire into
cakes of desired size.
NOTE: - Soaps from ground nut oil as well as coconut oil are prepared by same
procedure.
PRECAUTION:
Caustic soda is very corrosive and should not, therefore, be touched
with bare hands.
COMPARISON OF THE FOAMING CAPACITIES
OF THE TWO SOAP SAMPLES:
1. Take 0.1g of each soap sample in two test tubes numbered as 1 and 2.
2. Add 5ml of distilled water in each test tube and shake them vigorously for 2-3
minutes preferably in a shaker.
3. Place the test tubes in a test tube stand and start the stop watch.
4. Note the time when the foam in each of the tubes disappears.
12. Foaming capacity of that soap sample will be greater in which case it takes
longer time to disappear.
FOAMING CAPACITY OF DIFFERENT SOAPS
INTRODUCTION:
Soaps and detergents are used for removing grease and dirt from our clothes.
But all soaps are not equally effective in their cleansing action.
Soaps are the sodium or potassium salts of higher fatty acids such as palmitic
acid (C15H31COOH), stearic acid (C17H35COOH), oleic acid (C17H35COOH)
etc.,their general formula being RCOONa or RCOOK where R is the longer chain
alkyl group i.e. C15H31, C17H33 etc., thus, each soap molecule consists of two parts –
a lipophilic (oil soluble) part R and a hydrophilic (water soluble) part COONa or
COOK. The cleansing action of the soap depends upon the solubility of the long
alkyl are in grease or oil droplets and that of –COONa or –COOK part in water.
The dirt is held on the surface of the cloth by grease or oil droplets.
Whenever soap is applied on a dirty wet cloth, the non-polar alkyl group dissolves
in grease (non-polar) while the polar –COONa group dissolves in water (polar).
In this way an emulsion is formed between grease and water which appears as
foam. The dirt along with the emulsion is washed away when the cloth is treated
with excess of water.
Thus, the washing capacity of soap depends upon its foaming capacity, i.e.
the extent to which it produces foam with water. The foaming capacity also
depends upon the quality of water used. If soft water is used, soaps easily produce
lot of lather. On the other hand, if hard water is used, even good quality soaps will
not produce lather. The reason being that hard water contains magnesium and
calcium ions which form insoluble magnesium and calcium salts of carboxylic
acids which in turn, precipitate out in the form of a scum.
2C17H35COONa + Ca2+ → (C17H35COO)2 Ca↓ + 2Na+
(Water Soluble) (ppt.)
13. 2C17H35COONa + Mg2+ → (C17H35COO)2 Mg ↓ + 2Na+
(Water Soluble) (ppt.)
However, if hard water is first treated with Na2CO3, magnesium and calcium
ions present in it and precipitate as their insoluble carbonates. The filtrate can be
used for washing purposes since it is now rendered soft.
In contrast, detergents can be used for washing purposes even in hard water. The
reasons being that detergents are sodium or potassium salts of aliphatic or aromatic
sulphonic acids and even their calcium and magnesium salts are soluble in water
and thus do not form scum but form foam when treated with hard water.
EXPERIMENT:-
OBJECTIVE:
To compare the foaming capacity of different soaps.
APPARATUS:
Five 100ml conical flasks, five 20ml test tubes, 100ml measuring cylinder, test
tube stand, weight box and stop watch.
CHEMICALS REQUIRED:
Five different samples of soap, distilled water.
THEORY:
The foaming capacity of soap depends upon the nature of the soap and its
concentration. This may be compared by shaking equal volumes of the solutions of
the different samples of soaps having the same concentration with the same force and
for same period of time. The solutions are then allowed to stand when the foam
produced during shaking disappears gradually. The time taken for the foam to
disappear in each sample is determined.The longer the time taken for the
14. disappearance of foam in the given sample of soap, greater is its foaming
capacity or cleansing capacity.
PREOCEDURE:
1. Take five 100ml conical flasks and number them as 1, 2, 3, 4 and 5. Put 50ml of
distilled water in each of conical flasks and add 5gm of soap shavings or granules of
different soap samples to each flask.
2. Warm the contents of each flask to get a clear solution.
3. Take five 20ml test tubes and add 10ml of distilled water to each one of them and
label them as 1, 2, 3, 4 and 5. Now add 1ml of soap solution from each conical flask
to the corresponding test tube.
4. Close the mouth of the test tube number 1 with your thumb and shake its contents
vigorously for one minute. Place test tube in the test tube stand and start the stop
watch immediately. Note the time taken for disappearance of the foam produced.
5. Repeat the same procedure for test tubes 2, 3, 4 and 5 shaking each time with the
same force and for the same time (one minute). Note the time taken for disappearance
of foam in each case and record the observations in a tabular form.
OBSERVATIONS:
Amount of each soap sample taken = 5.0gm
Volume of distilled water added to each soap sample = 50.0ml
Test Tube
Number
Name of the Soap
Sample
Volumeof Soap
Solution Added
Volume of
Water Added
Time of disappearance
of foam
1. Dove 1.0ml 10.0ml
2. Lifebuoy 1.0ml 10.0ml
3. Dettol 1.0ml 10.0ml
4. Lux 1.0ml 10.0ml
5. Liril 1.0ml 10.0ml
6. Medimix 1.0ml 10.0ml
RESULT:
The foaming capacity and hence the cleansing capacity of different samples of
soaps is in the order:
15. Lifebuoy > Dettol > Liril > Lux > Medimix > Dove
PRECAUTION:
Each test tube containing the soap solution must be shaken with the
same force and for the same period of time.
TEXT BOOK OF CLASS 12th
CHEMISTRY
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