Soaps free carbonate alkali

Free Carbonate Alkali. This may be determined by difference from total free alkali and free caustic alkali and, except for direct determination of carbon dioxide by any of the recognised methods, this is the only way for potassium soaps. The carbonate in sodium soaps can be determined by the usual alcohol-insoluble method. 

Tikis ash contains carbonate of soda sometimes to tho amount of ninety-five or ninety-six per cent, It is, however, essentially necessary in the production of soap, that the alkali should bo rendered caustic—-that Is, set free from combination by the removal of carbonic acid as, if it be in chemical union with any other body, it has no decomposing power over the oils or fats. Even if combined with the weakest acids, saponification will not ensue and the greatest care should, therefore, be exercised in tin s preliminary process—the preparation of the lies. The process for causticlzing is the same in principle for tile preparation both of soda and potassa lies, It depends upon tiro greater affinity of lime than of soda or potassa for carbonic acid, and the decomposition is one of tho most simple, thus—... 

Free Caustic Alkali. As potassium carbonate was found to be appreciably soluble even in dehydrated ethanol, direct titration methods for potash soaps are impracticable, but for sodium soaps only slightly high results are obtained. 

Acylglycerols can be hydrolyzed by heating with acid or base or by treatment with lipases. Hydrolysis with alkali is called saponification and yields salts of free fatty acids and glycerol. This is how soap (a metal salt of an acid derived from fat) was made by our ancestors. One method used potassium hydroxide potash) leached from wood ashes to hydrolyze animal fat (mostly triacylglycerols). (The tendency of such soaps to be precipitated by Mg and Ca ions in hard water makes them less useful than modern detergents.) When the fatty acids esterified at the first and third carbons of glycerol are different, the sec-... 

In a study of the adsorption of soap and several synthetic surfactants on a variety of textile hbers, it was found that cotton and nylon adsorbed less surfactant than wool under comparable conditions (77). Among the various surfactants, the cationic types were adsorbed to the greatest extent, whereas nonionic types were adsorbed least. The adsorption of nonionic surfactants decreased with increasing length of the polyoxyethylene chain. When soaps were adsorbed, the fatty acid and the alkali behaved more or less independently just as they did when adsorbed on carbon. The adsorption of sodium oleate by cotton has been shown independently to result in the deposition of acid soap (a composition intermediate between the free fatty acid and the sodium salt), if no heavy-metal ions are present in the system (78). In hard water, the adsorbate has large proportions of lime soap. 

Free Alkali,—Some analysts determine the alkalinity to phenol-phthalein of the alcoholic soap solution without filtering, and express it as free alkali (caustic, carbonates, or any salt having an alkaline reaction). 

Combined Alkali.—The difference between total alkali and free alkali (caustic and carbonate together) represents the alkali combined with fatty acids. This figure may also be directly determined by titrating, with N/2 acid, the alcoholic solution of soap after the free caustic estimation, using lacmoid as indicator. 

The alkali metal soaps have been used for at least 2300 years. Their use as articles of trade by the Phoenicians as early as 600 b.c. has been documented. They were also used by the Romans, although it is generally felt that their manufacture was learned from the Celts or some Mediterranean culture. Early soap producers used animal fats and ashes of wood and other plants containing potassium carbonate to produce the neutralized salt. As the mixture of fat, ashes, and water was boiled, the fat was saponified to the free fatty acids, which were subsequently neutralized. 

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