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Soap

Characteristics And Uses Of Soap

Soaps are excellent cleansing agents and have good biodegradability. A serious drawback which reduces their general use, is the tendency for the carboxylate ion to react with Ca+ and Mg+ ions in hard water. The result is a water insoluble salt which can be deposited on clothes and other surfaces. These hard water plaques whiten fabric colors and also create rings found in sinks and bath tubs. Another problem with using soaps is their ineffectiveness under acidic conditions. In these cases, soap salts do not dissociate into their component ions, and this renders them ineffective as cleansing agents.

Although primarily used for their cleansing ability, soaps are also effective as mild antiseptics and ingestible antidotes for mineral acid or heavy metal poisoning. Special metallic soaps, made from soap and heavier metals, are used as additives in polishes, inks, paints, and lubricating oils.

See also Emulsion.

Resources

Books

Boys, C.V. Soap Bubbles: Their Colors and Forces Which Mold Them. New York: Dover: 1959.

Fishbein, Morris, ed. Medical Uses of Soap. Philadelphia: J.B. Lippincott, 1945.

Garrett, H.E. Surface Active Chemicals. New York: Pergamon Press, 1972.

Levitt, Benjamin. Oil, Fat and Soap. New York: Chemical Publishing Co., 1951.

Perry Romanowski
Randy Schueller

KEY TERMS

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Carboxylic acid

—A compound containing a carbon atom chemically bonded to two oxygen atoms.

Continuous process

—A method of manufacturing soap which involves removing glycerin during the reaction between fats and oils and caustic soda.

Emulsifier

—Chemical which has both water soluble and oil soluble portions and is capable of forming nearly homogenous mixtures of typically incompatible materials such as oil and water.

Fatty acid

—A carboxylic acid which is attached to a chain of at least eight carbon atoms.

Full-boiled process

—A method of manufacturing soap which involves boiling fats and oils with caustic soda.

Micelle

—Particle formed when the molecules of an emulsifier surround oil droplets allowing them to be dispersed in water.

Saponification

—A chemical reaction involving the breakdown of triglycerides to component fatty acids, and the conversion of these acids to soap.

Triglycerides

—A molecule containing three fatty acids chemically bonded to a glycol molecule.

Additional topics

Science EncyclopediaScience & Philosophy: Adam Smith Biography to Spectroscopic binarySoap - The History Of Soap, What Is Soap?, How Is Soap Made?, How Does Soap Work?