The mechanism of soap preparation process Essay

In this experiment, the soap is made from the cooking oil. The cooking oil contained triglyceride. Triglyceride which are triesters consist of fatty acid and glycerol (James, A. K., 2012). Triglyceride is basic raw material to produce soap and it is renewable sources which can be found in plant and animal.
The mechanism involved in the preparation of soap is saponification. These triglycerides react with the bases sodium hydroxide (NaOH) or potassium hydroxide (KOH) to produce glycerine and sodium salt of fatty acid. This process is called saponification. The bases will hydrolysed the fat. Fats and oils are hydrolyzed (split) to yield crude fatty acids and glycerine. This method involves heating fats and oils which reacting them with a liquid alkali to produce soap and water and glycerine. As overall, the fat molecule is reacting with 3 molecules of bases to produce 3 molecules of salt or soap and 1 molecules of glycerol (Eben, S.D., et al., 1994).
The salt obtained from this process is depended on the bases used. If the bases NaOH is used, sodium salt is obtained which is known as hard salt, it will produce hard soap. The sodium hydroxide makes bar soap which is solid, opaque bar soap. If the base, KOH is used, potassium salt is obtained which is known as soft salt, it will produced soft soap. Potassium hydroxide often called "potash" makes liquid soap which is flowing, clear or translucent liquid soap (Spencer, L. S., & Michael, R. S., 2013). Glycerine is very valuable by product of soap, can be used as a good moisturizer. The different in uses of bases, which are KOH and NaOH, will produced differ types of soap. The molecule of potassium is larger and heavier than sodium, therefore the bonds for potassium is weaker as compared to sodium.
In the experiment, ethanol is used. It is to create soap with a see-through, glass-like look, especially with glycerin soap. Ethanol also is used to make bars of hard soap. The soap produced when using ethanol is solid soap. If no ethanol is used in the making of the soap, the soap produced will be semi solid. When the ethanol is used, there will be foam or bubble produced while when there is no ethanol used, the soap produced will be no foam form. All the soap produced smell greasy which is because of the cooking oil used.
When ethanol and NaOH is added to the oil, it is heated until the precipitation of white solid form. The white solid precipitation is the salt form from the saponification process. It is then washed with the NaCl or sodium chloride solution. The process is called salting out. The NaCl solution causing the mixture to separate out into two layer which is soap on the top layer and glycerine in the bottom layer, as the soap is not very soluble in salt water. It increased the density of the solution and causes the soap to precipitate and float on the surface of the solution.