INTRODUCTION
A
soap is a salt of a compound, known as a fatty acid. A soap molecule has a long
hydrocarbon chain with a carboxylic acid group on one end, which has ionic bond
with metal ion, usually sodium or potassium. The hydrocarbon end is non polar
which is highly soluble in non-polar substances and the ionic end is soluble in
water. The structure of the soap molecule is represented below:
The
cleaning action of soaps because of their ability to emulsify or disperse water-insoluble
materials and hold them in the suspension of water. This ability is seen from
the molecular structure of soaps. When soap is added to water that contains oil
or other water-insoluble materials, the soap or detergent molecules surround
the oil droplets. The oil is, dissolved in the alkyl groups of the soap
molecules while the ionic end allows it to be dissolved in water. As a result,
the oil droplets are to be dispersed throughout the water and can be washed
away. A number of things affect the soap-making process and the quality of this
soap produced. The characteristics of this soap depend on the quality of oil,
and the amounts of the caustic soda and water used to make it. The speed of the
reaction between the oil and the caustic soda is influenced by free fatty acid
content of the oil, the heat of the components before mixing, and how
vigorously the mixing is to be done. Free fatty acid contents, vigorous mixing,
and heat, speed up the given soap-making process.
MATERIALS
60mL of 6M NaOH solution
17.5g of fat (coconut oil, corn oil, palm oil, margarine, butter)
75mL of distilled water
300mL of sodium chloride (NaCl) solution
100mL graduated cylinder
400mL beaker
250mL beaker
stirring rod
color and fragrance
PROCEDURE
1. 40mL of 6M NaOH and 17.5g fat was placed in 250mL beaker.
2. The mixture was heated slowly while stirring constantly for 20 minutes until all the water evaporated.
3. Then the remaining NaOH was added carefully, then boiled until all the water has boiled off.
4. When the crude soap cools, 12.5mL of distilled water was added and 50mL of hot and saturated NaCl solution was added.
5. The mixture was stir, and the lump was breaked.
6. The mixture was filtered using wire screen to trap soap small particles.
7. The soap was press between two filtered paper to removed as many water as possible.
RESULT
DISCUSSION
60mL of 6M NaOH solution
17.5g of fat (coconut oil, corn oil, palm oil, margarine, butter)
75mL of distilled water
300mL of sodium chloride (NaCl) solution
100mL graduated cylinder
400mL beaker
250mL beaker
stirring rod
color and fragrance
PROCEDURE
1. 40mL of 6M NaOH and 17.5g fat was placed in 250mL beaker.
2. The mixture was heated slowly while stirring constantly for 20 minutes until all the water evaporated.
3. Then the remaining NaOH was added carefully, then boiled until all the water has boiled off.
4. When the crude soap cools, 12.5mL of distilled water was added and 50mL of hot and saturated NaCl solution was added.
5. The mixture was stir, and the lump was breaked.
6. The mixture was filtered using wire screen to trap soap small particles.
7. The soap was press between two filtered paper to removed as many water as possible.
RESULT
 |
| Corn oil |
 |
| Sunflower oil |
 |
| Butter |
 |
| Margarine |
 |
| Palm oil |
Chemically, soap is a salt of a fatty acid. Soaps are mainly
used as surfactants for washing, bathing, and cleaning but they are also used
in textile spinning and are important components of lubricants. When we were
conducting this experiment, some precautions steps had been taken such as we
always wear eye protection (goggles) and rubber gloves. Clothing also should
consist of long sleeve shirt, long pants and socks and shoes. Beside that,
avoid breathing the dust released and fumes created when adding sodium
hydroxide to water. Moreover, do not use aluminum pans, utensils, or foil with
soap recipes that require the use of sodium hydroxide since these chemicals
will react with aluminium and always add sodium hydroxide slowly to water.
This project is an application to our experiment
saponification. In this project, we had make our own soap by following the
procedures given to us. We were given the opportunity to make our own shape of
soap, put any fragrance and colour to the soap. The soap is being pressed between
two sheets of paper to allow water removal and being left for two days. After
two days, the papers were removed and the soap was obtained.
CONCLUSION
In this experiment, we are able to make our own soap by
using sodium hydroxide and fat. This reaction is exothermic and the white
suspension formed is made up of soap and fat. The process of formation of soap
is called saponification.
QUESTION
1. Why
do soaps disperse grease?
Soaps
can disperse grease with water because part of the soap is soluble with grease
and part of it is soluble with water. Soap combines with both grease and water
and washes away in a shower. Combine the 2 and you get rid of the both. Part of
the soap molecule is similar to grease and combines, with grease,another part
of the soap molecule easily combines with water. Soap is a surfactant and combines
with both grease and water.
REFERENCES
1. Bryan Wright Chem 102 Lab Section 28. Project 17-SOAP Lab Report, February 25,
2010.
2. http://www.laney.edu/wp/cheli-fossum/files/2012/01/13-Saponification.pdf
3. http://amrita.olabs.edu.in/?sub=73&brch=3&sim=119&cnt=2
