Saponification - Preparation of Soap by Saponification Objective The purpose of this experiment is to prepare soap by saponification of a

Saponification - Preparation of Soap by Saponification...

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Preparation of Soap by Saponification Objective: The purpose of this experiment is to prepare soap by saponification of a triacylglycerol (a fat). In addition, some properties of soaps and detergents will be investigated. Safety Tips: Wear visorguards at all times while in the laboratory. HANDLE ALL SOLUTIONS WITH CAUTION. If acid and/or base is spilled on the counter top, clean it up immediately. IF A CHEMICAL IS SPILLED ON THE SKIN, IMMEDIATELY RINSE THE AREA WITH LARGE AMOUNTS OF WATER. Dispose of all solutions per instructor's directions. ANY sodium hydroxide solution spilled on the skin should be washed off IMMEDIATELY with large quantities of water. The dissolution of sodium hydroxide is a highly exothermic reaction. The temperature of this solution can reach 80 o C or higher. Therefore, handle HOT beakers with care. Background: Soaps, until the 19th century, were commonly prepared from animal fats or vegetable oils. Soaps and detergents are cleansing reagents, specifically surfactants that react on the surface of materials. Surfactants, depending on their chemical composition, are commercially used as either wetting agents, emulsifiers, dispersing agents, penetrants, anti-foaming reactants and/or cleansing reagents. Commercially available soaps and detergents are actually chemical compounds containing a variety of additional reagents to enhance their "cleaning ability" and/or target a specific cleaning purpose. Hair shampoos and antibacterial soaps are examples of such special purpose detergent products. The cleansing action of soaps and detergents come from their chemical make up and structure. A soap is the sodium or potassium salt of a long-chain fatty acid. The fatty acid usually contains 12 to 18 carbon atoms. Soaps consist of a nonpolar end (the hydrocarbon chain of the fatty acid) and a polar end (the ionic carboxylate). Because "like dissolves like", the nonpolar end (hydrophobic or water-hating part) of the soap molecule can dissolve the greasy dirt, and the polar or ionic end (hydrophilic or water-loving part) of the molecule is attracted to water molecules. Therefore, the dirt from the surface being cleaned will be pulled away and suspended in water. This structural combination of hydrophobic/hydrophilic components results in soap molecules forming drop like micelles. Micelles have hydrophobic interiors and hydrophilic exteriors.

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