LAB PROJECT 4: MAKING SOAP

BIOCHEMISTRY SBK3013

LAB PROJECT 4: APPLICATION: MAKING SOAP

MAUREEN SANTIH ANAK AMBANG	D20141067070
SHARIFAH AWANIS BINTI SYED MOHD ASWAD	D20141067053
HEIDI AMELDA ANAK LAGAT	D20141067086

DATE OF EXPERIMENT: 26 APRIL 2017

LECTURER: ASSOCIATE PROFESSOR ROSMILAH BINTI MISNAN

INSTRUCTOR: NUR ATIEKAH BINTI AZAHARI

Title: Application: Making soap

Objective:

1 

To study the saponification reaction for preparation of soap.

Introduction:

 Natural soaps are sodium or potassium salts of fatty acids, originally made by boiling lard or other animal fat together with lye or potash (potassium hydroxide). Hydrolysis of the fats and oils occurs, yielding glycerol and crude soap. Soaps and detergents are essential to personal and public health. They safely remove germs, soils and other contaminants and help us to stay healthy and make our surroundings more pleasant.   Soaps are made from fats and oils or their fatty acids.

Soaps are sodium or potassium salts of long chain fatty acids. When triglycerides in fat/oil react with aqueous NaOH or KOH, they are converted into soap and glycerol. This is called alkaline hydrolysis of esters. Since this reaction leads to the formation of soap, it is called the saponification process.

Materials:

*60 ml of 6 M NaOH solution

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

75 ml of distilled water

**300 ml hot sodium chloride (NaCl) solution

100-ml graduated cylinder

400-ml beaker 250-ml beaker Stirring rod

* Color and fragrance

* To make 6 molar sodium hydroxide, dissolve 19.2 grams of NaOH in enough water to make a total volume of 80 ml.

** This is just a saturated solution of NaCl.

Methods:

1. 40 ml of the 6 M NaOH and 17.5 g fat placed in a 250-ml beaker.

2. Heat to boil over the lowest flame that will sustain the boiling process. The mixture was stirredconstantly to avoid spattering. If spattering occurs, the flame removed and stirring the mixture continually. The flame Replace and heating continued after the spattering stops.

3. Boiling and stirring continued for about 20 minutes, or until it appears that most of the water has been evaporated.

4. Then the remaining 20 ml of NaOH solution carefully added and boiling continued for an additional 20 minutes or until most of the water has boiled off. DO NOT LET IT BOIL DRY.

5. As the crude soap cools, a waxy solid should form. About 12.5 ml of distilled water and about 50 ml of hot and saturated NaCl solution was added.

6. The mixture was stirred, breaking up lumps with your stirring rod.

7. The wash solution decanted by pouring it through a wire screen, which will trap small soap particles.

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

Results:

Palm oil

 Butter

 Sunflower oil

 Butter (our group)

Corn oil 

Discussion:

In this experiment, we used butter to make soap. Butter have high molecular weight and contain alcohol which is glycerol. Chemically, butter contain triglyceride. So, we can use butter to do saponification which is a process to make soap.

As for the results, our soap lost too much of water during boiling process. So, our soap becmme powder as the detergent. So, we do not need to forming a shape to our soap. We only decorate our soap by using the materials that we brought from home.

We only add some colouring using the dye provided. The scent of the soap, we got from the perfume that we brought from home.

Questions:

1. What are relationships between saponification and phase (liquid/solid) of a triglyceride?

The reactants must be in same phase in order for the chemical reactions to occur. The higher the concentration of the reactants, the more opportunity they may react and the faster the reaction. In this experiment, the hydroxide is mostly entire in the aqueous phase while the triglyceride mostly entire in the organic phase. For the hydroxide and triglyceride to be together, increasing the stirring will create more interface for the reaction to proceed. Glycerin and fatty acid salts will be produced as the reaction continues which can have appreciable solubility in both phases. As a result, the reagents will increase in concentration in the phase most favoured by the other as the reaction progresses.

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

Triglycerides with a long fatty acids have more mass. Long chain fatty acids also have relatively fewer number of carboxylic functional groups per unit mass and result in high molecular weight. The higher the mass, the lower the saponification number. As the saponification number is low, less amount of HCL is needed per gram of fat hydrolysed and KOH volume to hydrolysed the ester bond.

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 is equivalent to the molar amount of KOH used to saponify the test sample?

This is because 0.5M KOH has been react with 0.5M HCL. Therefore, the sample test require less acid to neutralize it because the KOH has been used to saponify the fat in the test sample.  Control sample require less HCL to neutralize it because the KOH has not been used as there are no fats in the blank sample.

4. Why do soaps disperse grease?

Soap can mix with both water and with oil. The soap molecule has two different ends, one that is hydrophilic (polar head) that binds with water and the other that is hydrophobic (non-polar hydrocarbon tail) that binds with grease and oil.

Conclusion:

Saponification is a chemical reaction between a base and an acid. That being said, this experiment was done in order to come up with an actual soap product.

References:

Science Buddies Staff. (2017, February 17). The Chemistry of Clean: Make Your Own Soap to Study Soap Synthesis. Retrieved April 29, 2017 from http://www.sciencebuddies.org/science-fair-projects/project_ideas/Chem_p096.shtml

amrita.olabs.edu.in,. (2013). Saponification-The process of Making Soap. Retrieved 30 April 2017, from amrita.olabs.edu.in/?sub=73&brch=3&sim=119&cnt=1

Thomas E. Thompson (2005). Lipid | Biochemistry | Britannica.com. Retrieved 30 April 2017. from https://global.britannica.com/science/lipid

Helmenstine, P. A. (2015). Definition of Saponification. Retrieved May 01, 2017, from https://www.thoughtco.com/definition-of-saponification-605959

Reflection:

Maureen- In this experiment, we used butter as a sample to make the soap. However, due to the error that we make during the experiment, the soap that we obtained from the experiment become “detergent-like” because of the overheating during the experiment. This experiment also required patience because we need to constantly stirring it to avoid spattering for several minutes. From this experiment, I learned new skills that is to make soap creatively.

Awanis: I found that this experiment is very interesting because we need to create own soap by using the procedure provided. Although the procedure takes a long time and patience, we manage to do it with our effort. We choose butter as the sample to make our soap. Lastly, our soap did not become soap, but it became detergent because of less of water content in the soap. We feel a bit disappointed about it.

Heidi- This laboratory project was very interesting. I have learnt how to make soap from butter. I never done this experiment before. So it something new to me. During the experiment, we faced some problems such as we cannot shape the soap into the shape that we like because our soap became very dry and hard to shape it. It became powder soap but it is okay because that is our own effort to make the soap. It was an interesting experience during this experiment.