Saponification: Sodium Hydroxide and Soap

1. Functions of Soap

Soap mostly acts as a dirt remover and a cleanser. It is utilized in bathing, cleaning, and likewise as a lube. Oil, grease, and other types of dirt do not dissolve in water. Alternatively, soap can suspend these in such a method that it can be discarded through its capability to serve as an emulsifying agent. This emulsifying agent makes it possible for the dispersion of liquid into another immiscible liquid. In this way, oil does not combine with water whereby able to cause dirt.

2. Raw products and soap making

Soap making needs two major raw materials:
* Fats and oils
Fats and oils are esters of fats and glycerol. These are acquired from natural compounds which are categorized into three: a. Nut oils Cold process soap making is the most ideal for this kind of oil which is also characterized by big percentage of fatty acids. Nut oils saponify quickly with strong alkali soulution. Example: coconut oil, palm kernel oil

b. Hard fats
Slow-lathering soaps are the ones produced with these fats and are first saponified with weak alkali, then more powerful alkali in the lasts. Example: palm oil, animal tallow oil, hydrogenated oil

c. Soft oils
These include significant amounts of unsaturated acids which can not produce hard soap and are generally combined with nut oils. They form excellent detergents and they lather easily. Example: groundnut, castor, cotton seed, fish oil, olive oil

* Alkalis

In soap making, two alkalis are typically used:
a. Caustic soda
It is very corrosive to the skin and readily takes in moisture.

b. Caustic potash
Compared to soda, potash is much more powerful in chemical response. It is typically used for making liquid soaps, shampoos and soft soaps since it produces soap of soft consistency and higher solubility in water.

Other basic materials:
* Builders
These are basically utilized to develop soaps. Examples of alkali contractors are sodium carbonate, sodium silicate and sodium sulfate.

* Fillers
Fillers increase the bulk of soap by adding weight, therefore reducing the production expense. Clay, kaolin, talc, starch, typical salt, chalk and magnesium carbonate are the most frequently used fillers in soap making. * Typical salt (Salt water).

It is used to separate out glycerin and excess caustic from the authentic soap.
* Colors
Color is added to make the soap more enticing and also to mask its original color. e.g. methyl violet, bismark brown, rhodamine, zinc oxide, chrome green, cadmium yellow, ultramarine, eosin and vermilon

* Perfumes

Since oils and fats contribute to the unpleasant odor of the soap, perfume is added to add fragrance. e.g. clove oil, vanillin, lemon grass oil, citronella oil

3. Describe the saponification process and include the chemical reaction Saponification is the process wherein esters undergo base-promoted hydrolysis. It is the alkaline hydrolysis of triacylglycerols, leading to glycerol and a mixture of long-chain carboxylic acids:

Nucleophilic addition-eliminatiion at the acyl carbon is the mechanism for base-promoted hydrolysis of ester. Reacting an ester with aqueous sodium hydroxide yields alcohol and the sodium salt of the acid. This reaction is done through boiling of fats and oils in aqueous sodium hydroxide until hydrolysis is complete. In the process of saponification, hydrogen atoms are released from the bonds and this is where the fats are hydrolyzed. The salts of long-chain carboxylic acids are the soaps which is the end-product of the reaction. Soap will precipitate when sodium chloride is added to the mixture. And through several reprecipitations, crude soaps are usually purified.

4. Flowchart on soap-making, outline the process