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I’d like to express my greatest gratitude to the people who have helped & supported me throughout
my project. I’ m grateful to Sir Francis Xavier for his continuous support for the project, from initial
advice & encouragement to this day.
Special thanks of mine goes to my colleague who helped me in completing the project by giving
interesting ideas, thoughts & made this project easy and accurate.
I wish to thanks my parents for their undivided support & interest who inspired me & encouraged me
to go my own way, without which I would be unable to complete my project. At last but not the least I
want to thanks my friends who appreciated me for my work & motivated me and finally to God who
made all the things possible…
S. no.
Page No.
Soaps are sodium or potassium salts of higher fatty acids like stearic, palmitic and oleic acids can be
either saturated or unsaturated. They contain a long hydrocarbon chain of about 10-20 carbon with
one carboxylic acid group as the functional group.
A soap molecule a tadpole shaped structure, whose ends have different polarities. At one end is the
long hydrocarbon chain that is non-polar and hydrophobic, i.e., insoluble in water but oil soluble. At
the other end is the short polar carboxylate ion which is hydrophilic i.e., water soluble but insoluble in
oil and grease.
Long Hydrocarbon Chain Hydrophobic end
Hydrophilic end
When soap is shaken with water it becomes a soap solution that is colloidal in nature. Agitating it
tends to concentrate the solution on the surface and causes foaming. This helps the soap molecules
make a unimolecular film on the surface of water and to penetrate the fabric. The long non-polar end
of a soap molecule that are hydrophobic, gravitate towards and surround the dirt (fat or oil with dust
absorbed in it). The short polar end containing the carboxylate ion, face the water away from the dirt.
A number of soap molecules surround or encircle dirt and grease in a clustered structure called
‘micelles’, which encircles such particles and emulsify them.
Cleansing action of soaps decreases in hard water. Hard water contains Calcium and magnesium ions
which react with sodium carbonate to produce insoluble carbonates of higher fatty acids.
2C17H35COONa +Ca2+ (C17H35COO) 2 Ca
(Water soluble)
2C17H35COONa + Mg2+ (C17H35COO) 2 Mg
This hardness can be removed by addition of Sodium Carbonate.
Ca2++ Na2CO3 CaCO3 + 2Na+
Mg2++ Na2CO3 MgCO3 + 2Na+
To compare the foaming capacities of five different commercial soaps.
5 test tubes, 5 conical flasks (100 ml), test tube stand, Bunsen burner and stop watch.
5 different samples of soap and distilled water
The foaming capacity of a soap sample depends upon the nature of soap and its
concentration. This can be compared for various samples of soaps by taking the
same concentration of solution and shaking them.
The foam is formed and the time taken for disappearances of foam in all cases is
compared. The lesser the time taken by a solution for the disappearance of foam, the
lower is its foaming capacity.
Five conical flasks (100 ml each) are taken and numbered 1 to 5.
In each of these flasks equal amounts (say 5 gm) of the given samples of soap
shavings or granules are taken and 50 ml of distilled water is added.
Each conical flask is heated few minutes to dissolve all the soap completely.
In a test-tube stand, five big clean and dry test tubes are taken and numbered 1 to 5
One ml of the five soap solution is then poured in the test tubes of corresponding
10 ml. of distilled water is then added to each test tube.
Test tube no 1 is then shaken vigorously 5 times.
The foam would be formed in the empty space above the container.
Stop watch is
started immediately and the time taken for the disappearance of foam is noted.
Similarly the other test tubes are shaken vigorously for equal number of times (i.e., 5
times) with approximately with the same force and the time taken for the
disappearance of foam in each case is recorded.
The lesser the time taken for the disappearance of foam, the lower is the foaming
Amount of each soap sample taken
Amount of distilled water taken
= 5 gm.
= 50 ml.
Volume of each soap solution taken
= 1 ml.
Volume of distilled water added
= 10 ml.
Soap Sample
Time taken (seconds)
The soap for which the time taken for the disappearance of foam is highest
has maximum foaming capacity and is the best quality soap among the soaps
Study the effect of the addition of Sodium Carbonate (Washing Soda) on the
foaming capacity of different soap solutions.
3 test tubes, test tube stand, Bunsen burner and stop watch.
0.5 g sample of soap, water (distilled & tap both) and M/10 Na2CO3 solution.
When sodium or potassium soaps are put into water containing calcium and
magnesium ions (Hard water), results in formation of scum which applies grey
appearance on the cloth. To achieve the same washing or cleaning action, more soap
must be added.
2C17H35COONa +Ca2+ (C17H35COO) 2 Ca +2Na+
(Water soluble)
Hard water is water that has high mineral content (mainly calcium and magnesium
ions) (in contrast with soft water). Hard water minerals primarily consist of calcium
(Ca2+), and magnesium (Mg2+) metal cations, and sometimes other dissolved
compounds such as bicarbonates and sulphates. Calcium usually enters the water as
either calcium carbonate (CaCO3), in the form of limestone and chalk, or calcium
sulphate (CaSO4), in the form of other mineral deposits.
When Na2CO3 is added to tap water the calcium (Ca2+), and magnesium (Mg2+) ions
precipitate as their carbonates .i.e. foaming capacity of soap increases.
Ca2++ Na2CO3 CaCO3 + 2Na+
Mg2++ Na2CO3 MgCO3 + 2Na+
Dissolve 0.5g of soap and dissolve it in 50 ml of distilled water.
Take three test tubes and add distilled water in first, tap water in second and third
test tube.
Add 5 ml of M/10 sodium carbonate to third test tube.
To above test tubes add soap solutions separately.
Now shake first test tubes for formation of foam.
Now start the stop watch to calculate time taken for disappearance of foam.
Similarly, perform the experiment with other soap solutions. Record the
observations in a tabular form.
Amount of each soap sample taken
Amount of distilled water taken
= 0. 5 gm.
= 50 ml.
Volume of each soap solution taken
= 1 ml.
Volume of distilled water added
= 10 ml.
S. No.
Time taken (seconds)
Water used
Foaming capacity of soap in maximum in distilled water.
The foaming
capacity of soap increases on the addition of Sodium Carbonate.
Soap and cleanliness are inseparable, and cleansing, be it personal hygiene or
laundering, is part of human history. Stringent guidelines with regard to the cleanliness
of holy sites are a part of all the major religions, and the sanctification of the state of
cleanliness as well as its signification of purity of body and soul are recurrent themes in
their liturgies.
The origins of the word "soap" and of the first use of soap are obscure. According to one
Roman legend, soap was discovered serendipitously near Mount Sapo, an ancient
location for animal sacrifice not far from Rome. Animal fat mixed with wood ashes (the
ancient source of alkali) and rain-water created an excellent soap mixture. Roman
housewives noticed that the strange yellow substance in the water of the Tiber River
(flowing near Mount Sapo) made their clothes cleaner and brighter than ordinary water.
Soapmaking became an art among the Phoenicians (fl. ca. 600 B.C.E. ) and underwent
significant advances in Mediterranean countries in which local olive oil was boiled with
alkali ashes (as part of soapmaking) at around the same time.
Ascribing value to cleanliness seems to have been a part of the civilizing of humankind.
After the fall of Rome (in 467 C.E. ), a decline in attention paid to personal cleanliness
and the maintenance of sanitation contributed to the great plague of the Middle Ages,
and made especially grim contributions to the Black Death plague epidemic of the
fourteenth century. Cleanliness and regular bathing became unremarkable in much of
Europe not until 300 years later.
For several centuries in Europe, soapmaking was limited to small-scale production that
often used plant ashes containing carbonate ( esters of carbonic acid) dispersed in
water, which were then mixed with animal fat and boiled until the water evaporated.
The reaction of fatty acid with the alkali carbonate of the plant ashes formed a soap and
The real breakthrough in soap production was made in 1780 by a French chemist and
physician, Nicolas Leblanc, who invented the process of obtaining soda (sodium
carbonate, Na 2 CO 3 ) from common salt (the Leblanc process), and increased the
availability of this alkali at a reasonable cost. With the development of power to operate
factories, soapmaking grew from a "cottage industry" into a commercial venture and
became one of the fastest-growing industries of the modern era. Body soap, which had
been a luxury item affordable by royalty and the very rich, became a household item of
ordinary folks as well.
Throughout the nineteenth century, physicians were realizing the value of soap as a
medicinal agent. A well-known protagonist of soap was scientist and educator Ignaz
Phillipp Semmelweis, who in 1847 discovered the infectious etiology of puerperal fever
and therefore required medical students to wash their hands before they examined
patients. Semmelweis encouraged
Table 1. Ingredients of soaps and detergents.
Percent of Total by Weight
Plasticizers and binders
Lather enhancers
Fillers and binders
Opacifying agents
Dyes and pigments
his colleagues to adopt his antiseptic methods, telling them, "while we talk, talk, talk,
gentlemen, women are dying. I am not asking anything world-shaking. I am asking you
only to wash.… For God's sake, wash your hands." In a circular handed out in Budapest
during the summer of 1865, he implored new mothers: "Unless everything that touches
you is washed with soap and water and then chlorine solution, you will die and your
child with you!"
The chemistry of soap manufacturing stayed essentially unchanged until World War II,
at which time synthetic detergents (syndets) became available. There had been a search
for cleansing agents that would foam and clean when added to seawater in response to
the need of sailors who spent months at sea under severe freshwater restrictions.
The Chemistry of Soaps, Shampoos, and Laundry
Soaps, shampoos, and laundry detergents are mixtures of ingredients (see Table 1).
The surfactants are the essential cleaning substances and they determine the
cleansing and lathering characteristics of the soap, as well as its texture, plasticity,
abrasiveness, and other features. Surfactants are compounds that have a dual affinity:
They are both lipophilic and hydrophilic . A surfactant molecule consists of a
lipophilic tail group, which links to greasy soil, and a hydrophilic and polar head group,
which renders the molecule water-soluble; this arrangement helps to disperse and rinse
away greasy soil. Variations in the balance betweenhydrophobic and hydrophilic
features determine the use of the surfactant as a detergent, wetting agent ,
or emulsifier .
Surfactants are classified according to the nature of the hydrophilic head. There are four
main classes: anionic, cationic, amphoteric, and nonionic. The first three refer to
charged surfactant molecules. An anionic surfactant possesses a negative charge and
needs to be neutralized with an alkaline or basic material in order for its full detergent
capacity to be realized, whereas a cationic surfactant is positively charged and needs to
be neutralized by an acid. Amphoterics include both acidic (negative) and basic
(positive) groups, and nonionics contain no ionic constituents. "Natural" soap contains
an anionic surfactant. The majority of surfactants that are used in personal cleansing
bars and shampoos have anionic head groups.
It is noteworthy that almost all anionic surfactants are sodium or potassium salts of the
negatively charged head groups; thus the advertising slogans "alkali free" and "soapless
soap" are incorrect. Most soaps and shampoos contain a mixture of two to four
surfactants (out of the thousands of synthetic surfactants that are currently available).
In addition, there are innumerable plasticizers, binders, moisturizers, and fillers that are
also used to formulate these soaps and shampoos. Creation of the formula of a soap is a
complicated enterprise and it requires, in addition to a knowledge of chemistry and even
engineering, both imagination and inspiration. The contemporary formulation of soaps
is the result of research and development, as well as trial and error, carried out over a
course of many years by research teams. It is as much art as it is science, and it requires
a long learning experience.
The Process of Washing
The most obvious target of cleansing is the outermost layer of the skin, the keratinizing
epithelium. It is a cornified (hardened) cell envelope and it has an extremely tough
protein/ lipid polymer structure. This hard and lipophilic layer of the epidermis and the
surface hairs would not easily retain dirt if it were not for a hydrolipid film that covers
the outermost layer of skin and that picks up particles of soil. This natural outer film of
lipid entraps and glues environmental dust, pollutants, smoke, keratinous debris,
organic and inorganic compounds in sweat, cosmetics, and other substances that come
in contact with it. The hair of the scalp (corresponding to a surface area of about 8
square meters, or 86 square feet, for an average female head) is cleansed regularly. The
scalp gets coated with sebum, the product of the sebaceous appendages that flows into
hair follicles and a natural lubricating oil that contributes luster to the hair, on the one
hand, but entraps dirt, on the other.
Washing the skin consists of the removal of the outer layer of grease (lipid) in which the
soil (no matter what kind) is embedded. It is a complex physicochemical process that
includes the following:
1. A weakening of the binding forces between the keratinized epithelium and the
layer of grease via the reduction of the surface tension between the water and the
water-resistant oil/grease. Because of this reduced surface tension, water (and
surfactant molecules) can penetrate into the finest wrinkles of the skin. In this
way, more and more interface is occupied by surfactant, and the adhesiveness of
the soil-containing layer is further weakened, a process facilitated by mechanical
2. Transfer of portions of the layer of oil to the aqueous vehicle. It is facilitated by
the action of the micelles created when the soil was emulsified. The micelles have
negatively charged surfaces and are repulsed by the overall negative charge of the
keratin of the skin epithelium.
3. Dispersion/suspension of the oil and dirt particles in the soap foam, preventing
these particles from being redeposited on the surface.
The Interaction of Soaps with the Skin
Surgeons need to scrub. Health-care providers and employees of food services must take
a range of precautions against the dissemination of microorganisms. Very often, the
simple act of washing one's hands is not fateful but nevertheless wise. Most experts in
infection control and epidemiology maintain that hand washing remains the most
powerful defense against infections. Germs are all around us, and can linger anywhere:
the office phone, door handles, shopping baskets, money, even the button you push
when you call for an elevator. You can unknowingly come into contact with germs. One
simple rub of the eye or bite of a sandwich using unwashed hands can introduce any
number of illnesses into your body. Hand washing reduces the risk. At the same time,
most contemporary dermatologists agree that the comfortable classes have become
preoccupied with cleanliness. Less, not more, washing is better for the skin. However,
the irritant, toxic, and harmful effects of soaps have been exaggerated by some
advertisers. (After all, what better way to promote their "mild," "nonallergenic," and
"soapless" products?)
Washing with soap makes no discretely identifiable contribution to health. Its value lies
more in the feeling it engenders in the user. People derive great enjoyment from
washing: It gives them a tremendous sense of well-being.
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