APPLICATION: MAKING SOAP

DEPARTMENT OF BIOLOGY

FACULTY OF SCIENCE & MATHEMATICS

UNIVERSITI PENDIDIKAN SULTAN IDRIS

SBK3013

PRINCIPLE IN BIOCHEMISTRY

LABORATORY PROJECT 4

APPLICATION: MAKING SOAP

NAME	MATRIC NO.
MUHAMMAD FARIS BIN ISMAIL SAZEMI	D20141067089
MAYURIE PHUTHARANT A/P SURIN	D20141067078
NUR AFIQAH SYAHMINA BT MOHD KAMAL	D20141067091

GROUP: A

LECTURER’S NAME: DR. ROSMILAH MISNAN

INSTRUCTOR NAME: NUR ATIEKAH BT AZAHARI

INTRODUCTION

The ancients Egyptian around 1550 BC combined both animal and vegetable oils with alkaline salts to produce a soap-like substance. They used this mixture for treating sores, skin diseases as well as washing. Nowadays soaps are known as carboxylate salts with a very long hydrocarbon chains. Soap can be made from the base hydrolysis of a fat or oil. This process is called saponification, and the reaction has been known for centuries. Traditionally, soaps were made from animal fat and sodium hydroxide. Nowadays, soap can be made from different kind of oil and fats. Addition of fragrance and colour into the soap has produce varieties of soap.  In this experiment, we will be using different kind of oils and fat in order to make soap.

MATERIAL

60 ml of 6 M NaOH solution

17.5 g of fat (sunflower oil, corn oil, palm oil, margarine, butter)

75 ml distilled water

300 ml hot sodium chloride (NaCl) solution.

100 ml graduated cylinder

400 ml beaker

250 ml beaker

Stirring rod

Colour and fragrance

PROCEDURE

1.      40 ml of the 6 M NaOH and 17.5 g fat was placed into 250 ml beaker.

2.      The solution was heated to boil over the lowest flame that will sustain the boiling process. The mixture was stirred to avoid spattering.

3.      The mixture was boiling and stirring for 20 minutes, or until the water in the mixture has been evaporated.

4.      The remaining 20 ml of NaOH was added into the mixture and continues boiling the solution for 20 minutes or until most of the water was boiled off. Cannot let the mixture to boil dry.

5.      Let the crude soap to cool and a waxy solid should be form. Then 12.5 ml of distilled water and 50 ml of hot and saturated NaCl solution was added into the mixture.

6.      The mixture was stirred and the lump was breaking up using the stirring rod.

7.      The wash solution was decant by pouring it through a wire screen, to help trap the small soap particles.

8.      The wash process was repeated twice. After that, for the final washing the soap was been pressed between the two sheets of paper towelling to expel as much water as possible.

RESULT

Substance	Soap
Sunflower oil
Corn oil
Palm oil
Margarine
Butter

  

DISCUSSION

Soaps and detergent are essential to personal and public health. By using soap, it can remove germs, dirt and other contaminants and it also help us to stay healthy. It also make our surrounding more pleasant because by using soap, it will remove bad odour from our body. Basically, soap are made from fats and oils or their fatty acids. The fatty acids can be divided further into 2 groups that is saturated and unsaturated fatty acids. The saturated fatty acid contain only carbon-carbon single bonds meanwhile for the unsaturated fatty acids it contain multiple bonds between the carbon-carbon atom. Examples for saturated fatty acid is stearic acid and palmitic acid, meanwhile for the unsaturated fatty acids, examples are oleic acid.

Process that is involved in this soap-making is saponification. The process which the triglycerides reacted with sodium or potassium hydroxide to produce glycerol and fatty acid salt, ‘called soap’. When Sodium Hydroxide is used, a hard soap will be produced, meanwhile, when the potassium hydroxide is used, the resulting products is soft soap. Lipids that contain fatty acid ester linkages can undergo hydrolysis. This reaction is catalysed by a strong acid or base. Saponification is the alkaline hydrolysis of the fatty acid esters.

For example, when there is a chemical reaction between any fat and sodium hydroxide, it is called as saponification reaction. The chemical equation for the saponification process are as follows:

Triglyceride + sodium hydroxide (or potassium hydroxide) → glycerol + 3 soap molecules

The soap molecules has two parts that is hydrophilic head (polar part), and hydrophobic tails (non-polar part). The hydrophobic tails has water repelling properties meanwhile, the hydrophilic head has water loving properties.

There are two types of soap namely hard soap, and soft soap. The sodium salt of long chain fatty acid is known as hard soap. It is difficult to dissolve in water. It is used as laundry soap. The potassium salt of long chain fatty acid is known as soft soap, as it produces more lather. It is used as toilet soap and shaving soap. Since soaps have free alkali ions, they are alkaline in nature. Hence, the soap solutions are slippery to the touch.

QUESTION AND ANSWER

1. What is the relationship between saponification and phase (liquid / solid) of a triglyceride?

Saponification triglyceride is actually the reaction of triglycerides when they are turned into soap. Soap is produced when triglycerides react with a base like sodium. In technical terms, saponification involves base that is hydrolysis of triglycerides, which are esters of fatty acids, to form the sodium salt of a carboxylate. In addition to soap, such traditional saponification processes produces glycerol. "Saponifiable substances" are those that can be converted into soap. Depending on the nature of the alkali used in their production, soaps have distinct properties. Sodium hydroxide (NaOH) gives "hard soap", whereas, when potassium hydroxide (KOH) is used, a soft soap is formed.

2. Why do triglycerides with longer fatty acids have a lower saponification number than those with shorter fatty acids?

The triglycerides with longer fatty acid have lower saponification because the amount of KOH needed to break down the hydrolysis process is higher since the triglycerides have long chain of fatty acid. So, the titration shown the lower amount of KOH that react with HCL. The KOH left is unreacted KOH from the hydrolysis process.

3. Why is the difference in the molar amount of HCl used to neutralize the control and the amount of HCl used to neutralize the sample equivalent to the molar amount of KOH used to saponify the test sample?

In the control sample which is filled with KOH then titrated with the HCL, it will need a relatively large amount of HCL to neutralize it’s to form salt and water compare with the test sample. This is because, in the control, all of the HCL is needed to neutralize the KOH. Meanwhile, in the control sample, some KOH is used to hydrolyse the fatty acids while some is neutralized by HCl. Therefore, more HCl is utilized in the blank test than in the sample test.

4. Why do soaps disperse grease?

Grease are non-polar compounds, meanwhile water are polar molecules. The non-polar compounds cannot dissolve in the polar compound. This means that, grease cannot dissolve in the water if they are mixed. However, soap can mix with both water and the grease. This is because, the soaps has two different end that is hydrophilic head, and hydrophobic tails. The hydrophilic head (water-loving part) will attract the water molecules. Meanwhile, the hydrophobic tails (water-hating part) will attract to the grease. When greasy dirt is mixed with the soapy water, the soap molecules will arrange themselves into tiny clusters namely micelles. The hydrophilic head sticks to the water, forming the outer surface of the micelles. The hydrophobic tails will bind to the grease and the grease will trapped in the centre due to its nature that it cannot make contact with the water. With the oil tucked safely in the centre, the micelle is soluble in water. As the soapy water is rinsed away, the greasy dirt goes along with it.

CONCLUSION

In this experiment, we successfully produced soap by using the sunflower oil. Soap is one of the product produced by undergo the saponification reaction between sunflower oil and heated sodium hydroxide.

REFERENCES

Zumdahl, Steven S. (2009). Chemical Principles (6th ed.). New York: Houghton Mifflin Company

David, A. K. (2000). The science of soaps and detergents. Retrieved on May 1^st, 2017 from          http://www.chymist.com/Soap%20and%20detergent.pdf

Hill, J.W.; Petrucci, R.H.; McCreary, T.W.; Perry, S.S. (2005). General Chemistry (4th ed.). Upper Saddle River, New Jersey: Pearson Prentice Hall.

Fromm, H. J.&  Hargrove, M. (2012). Essentials of Biochemistry. Pearson Education