The process (similar to what we will be doing in lab) involved combining some form of fat with an alkali (basic) material. Most commonly the alkali was in the form of potash and pearlash, which contain KOH.

1. Name………..Shahrbano
#58
Soap formation by sponification Lab report
Introduction:
The process (similar to what we will be doing in lab) involved combining some form of fat with an
alkali (basic) material. Most commonly the alkali was in the form of potash and pearlash, which
contain KOH. Potash and pearlash soaps were used by everyone from the reigning monarchs to the
peasant or cottager, who made their own soap from the waste fats and ashes they saved.
Soap is produced by the saponification (hydrolysis) of a triglyceride (fat or oil). (See Figure 1.)
In this process the triglyceride is reacted with a strong base such as sodium or potassium
hydroxide to produce glycerol and fatty acid salts. The salt of the fatty acid is called a soap.
Fatty acids are straight-chain monocarboxylic acids. The most common fatty acids range in size
from 10-20 carbons and most often have an even number of carbon atoms including the carboxyl
group carbon. The carbon-carbon bonds in saturated fatty acids are all single bonds, while
unsaturated fatty acids have one or more carbon-carbon double bonds in their chains. One
example of a saturated fatty acid is palmitic acid, CH3-(CH2)14-CO2H.
Chemistry of soap:
As stated earlier, the chemistry behind soap-making was not understood for many years. It is
now known that saponification of soaps proceeds by the conversion of the triglycerides, which
are the components of fats and oils, to fatty acid salts and glycerol as show in Figure 1. The R
groups in the figure represent long carbon chains with the accompanying hydrogens. For each
specific triglyceride, these specific R groups can be determined.
CH2OCRCHOCRCH2OCROOO+ 3
NaOHΔNaOCRO3+CH2OHCHOHCH2OHa triglyceridein a fat or oilfatty
acid salt (soap)glycerol
Fatty acids are seldom found as free molecules in nature but are most often a part of a larger
molecule called a triglyceride. Triglycerides consist of a three-membered carbon chain (glycerol
backbone) with a fatty acid bonded to each of the three carbon atoms in the glycerol backbone.
The bond between the fatty acid and the glycerol backbone is referred to as an ester linkage. In
the saponification process the ester linkage is broken to form glycerol and soap.
Pure coconut oil yields a soap that is very soluble in water. The soap contains essentially the salt
of lauric acid with some myristic acid. It is so soft (soluble) that it will lather even in seawater.

2. Palm oil contains mainly two acids, palmitic acid and oleic acid, in about equal amounts.
Saponification of this oil yields a soap that is an important constituent of toilet soaps. Olive oil
contains mainly oleic acid. It is used to prepare Castile soap, named after the region in Spain in
which it was first made.
Toilet soaps generally have been carefully washed free of any alkali remaining from the
saponification. As much glycerol as possible is usually left in the soap, and perfumes and
medicinal agents are sometimes added. Floating soaps are produced by blowing air into the soap
as it solidifies. Soft soaps are made by using potassium hydroxide, yielding potassium salts
rather than the sodium salts of the acids. They are used in shaving cream and liquid soaps.
Scouring soaps have abrasives added, such as fine sand or pumice.
Apparatus and chemicals:
Beaker, flask, pipette, burette, test tube, measuring cylinder, stirrer, burner etc.
Fat/oil, 15 /10 ml of coconut oil, 20% solution of NaCl and 20% NaOH, phenolphthalein
indicator, 0.1M HCl, 15 ml ethanol, filter paper, pH strips etc
Procedure:
Part-1
15 ml coconut oil mix with a 15 ml ethanol and then mix with 20 % solution of NaOH and heat
it till all the liquid convert into thick soap. Add 10/15ml NaCl and filter it .
Fat + oil + NaOH = soap + glycerol
When a thick soap is formed dry it by placing on a filter paper and then keep in sun for several
min.when the soap became fully dry check it’s properties as
Texture- waxy appearance
pH- 10
Litmus paper test changes from red core to blue
Leather produce leather
Smell
Part-2: Now we prepare a soap sample for acid base titration as 2g of soap is mixes with water.
10ml of soap sample is taken into the titration flask and titrate it against HCl which was taken in
the burette.
Added phenolphthalein drop wise in the soap sample as initially the color of solution was pink
but when the acid was added drop wise from burette it became changes to colorless after a while.
Observations and calculations:

3. Formula: M1 .V1 = M2 . V2
𝑀1=
0.1×4.3
10
= 0.043M
Strength of NaOH= Molarity×Molar mass
= 0.043× 40
= 1.72 g/l
1000ml of soap solution have free alkali = 1.72g
100ml of soap solution have free alkali =
1.72
1000
× 100
= 0.172g
1g of soap have free alkali = 0.172g
100g of soap have free alkali =
0.172
1
× 100
=17.2%
Result;
In the preparation of soap by saponification 100g of soap contains free alkali is
17.2% .