Soap

CHEMISTRY SSS3 First term

WEEK 7

Soap

Performance objectives

Students should be able to:

1. Explain the preparation of soap.
2. Draw the structure of soap.
3. Explain the action of soap as an emulsifying agent.

Content

Soap

Soaps are sodium or potassium fatty acids salts, produced from the hydrolysis of fats in a chemical reaction called saponification.

Each soap molecule has a long hydrocarbon chain, sometimes called its 'tail', with a carboxylate 'head'. In water, the sodium or potassium ions float free, leaving a negatively-charged head.

Preparation of soap

On heating with sodium hydroxide, vegetable oil or animal fat forms a sodium salt of fatty acid (sodium stearate) and glycerol. This process is known as saponification.
vegetable oil or Animal fat …