Chemistry Project on Fatty Material of Different Soap Samples

Fatty Material of Different Soap Samples

Chemistry Project

(For Partial Fulfilment of AISSCE-2010)

Guided by: Mr. Hemant Pathak (PGT Chemistry)

Submitted by: Ayush Jain (Class XII)

School: Vivekanand Vidya Vihar, Maral Sarovar, Nimrani, Distt. Khargone (M.P.)

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Certificate

This is to certify that Master Ayush Jain of Class XII has completed his project on Finding the Percentage (%) of Fatty Material on Different Soap Samples.

He has successfully prepared this project report in the Chemistry laboratory of our school.

This project may be considered as partial fulfilment of AISSCE 2009-2010 conducted by the Central Board of Secondary Education, Delhi.

Mr. Hemant Pathak

External Examiner | Internal Examiner

Mr. K.K. Mukherjee, Principal

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Acknowledgement

It is my humble pleasure to acknowledge my deep sense of gratitude to Chemistry teacher Mr. Hemant Pathak for his valuable support, constant help and guidance at each and every stage, without which it would not have been possible to complete this project.

I am thankful again to Mr. Hemant Pathak of the Chemistry department for their co-operation in printing this project.

I am also thankful to Mrs. Kshipra Shukla, our Librarian, for the help provided in referring the required books.

I also register my sense of gratitude to our Principal Mr. K.K. Mukherjee for his immense encouragement that has made this project successful.

Ayush Jain Class XII

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Aim

Aim: To find and calculate the percentage of fatty material in different soap samples.

Procedure

1. Take 10 gm of each soap sample in which the percentage of fatty material has to be determined.
2. Prepare the solution of each soap in water.
3. Add 10 to 12 drops of HCl in each solution and heat the solution for 5 to 10 minutes.
4. Fatty matter floats on the soap solution surface by forming an upper layer and is collected by filter paper and weighed.
5. Collect the fatty material from each solution by filtration and again weigh the filter paper including the filtrate (fatty material). The fatty material is then dissolved in ether for calculating oil content.
6. Take the solution in a separating flask, and remove the solution except the oily material from the surface.
7. The remaining solution is exposed to sunlight to evaporate the ether from the solution.
8. The oily matter can now be easily weighed using a weighing machine.
9. The percentage of oily material can be calculated using the observations below.

Theory

Soap: Soaps are the sodium or potassium salts of higher fatty acids. The fatty acid contains a long chain of 16-18 carbon atoms.

Structure of Soap

Soap contains two parts:

1. A long hydrocarbon chain, which is water repelling - called a non-polar tail.
2. An anionic part which is water attracting - called a polar head.

Soap may be represented as:

CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-COONa

Soaps are also made from animal fats and vegetable oils. Fats and oils are esters of higher fatty acids called glycerides. When oils and fats are heated with a solution of NaOH, they break down to the sodium salt of the respective fatty acid (soap) and glycerol. This process of making soap by hydrolysis of fats and oils with alkalis is called saponification. The soap is separated from the solution by addition of common salt (NaCl). Salt is added to the soap solution to decrease the solubility of soap, due to which soap separates out from the solution in solid form and starts floating on the surface. The crust of soap thus formed is removed and put into moulds to get soap cakes. The solution left behind contains glycerol and NaCl.

Limitations of Soap

Soap is not suitable for washing clothes with hard water because of the following reasons:

1. Hard water contains salts of Ca and Mg. When soap is added to hard water, Ca and Mg ions react with soap forming insoluble Ca and Mg salts of fatty acids.

2C17H35COONa + MgCl2 → (C17H35COO)2Mg + 2NaCl

2C17H35COONa + CaCl2 → (C17H35COO)2Ca + 2NaCl

Therefore a lot of soap is wasted when water is hard.

1. When hard water is used, soap forms insoluble precipitates of Ca and Mg salts which stick to the clothes being washed. This interferes with the cleansing ability of the soap and makes the cleansing process difficult.

Cleansing Action of Soap

The dirt in cloth is due to the presence of dust particles in fat or grease, which stick to the cloth. When the dirty cloth is dipped in soap or detergent solution, the soap and dust particles come into contact with each other. The non-polar tails of the soap begin to dissolve in the non-polar oil or grease while the polar head part remains directed toward the water. As more particles enter the grease, each fat or oil droplet is surrounded by a number of negatively charged polar heads and the similar charges repel each other. The oil or grease droplets break off and are still surrounded by the negatively charged polar heads of the soap molecule. As a result, the cloth gets free from the dirt and the droplets are washed away with water.

Difference Between Soap and Detergents

Soap	Detergents
Soaps are sodium salts of long chain carboxylic acids.	Synthetic detergents are sodium salts of long chain benzene sulphonic acid.
Soaps are not suitable for washing purpose when water is hard.	Synthetic detergents can be used for washing even when water is hard.
Soaps have relatively weak cleansing action.	Synthetic detergents have a strong cleansing action.

Observation

S.No.	Name of Soap	Weight of Filter Paper (A)	Weight of Filter Paper + Fatty Material (B)	Fatty Material (B-A)	Percentage (%)
1.	Santoor	0.3856	7.5856	7.2	72%
2.	Lux	0.2956	7.5956	7.3	73%
3.	Lux International	0.3203	7.2701	7.5	75%
4.	Lifebuoy	0.4701	7.2701	6.8	68%

Conclusion

Soap contains alkali matter, which affects our skin and may even cause the skin to crack. To maintain the oily and moisture balance on our skin, fatty material is required in soap. In general, the fatty matter in soap is approximately 70% to 80%. Fatty matter below 70% makes our skin dry, rough, and prone to cracking, whereas a highest percentage above 80% makes the soap sticky and oily and makes washing very difficult. From the table it is clear that Lux International is the best soap for bathing purpose because it contains the largest amount of TFM (maximum percentage of TFM).

Bibliography

• Introduction to Chemistry by Comprehensive.
• The Complete Reference Chemistry by S. Chand.
• Chemistry Tips by Nitesh Gupta.