Organic carboxylic acids

Ionic conductors arise whenever there are mobile ions present. In electrolyte solutions, such ions are nonually fonued by the dissolution of an ionic solid. Provided the dissolution leads to the complete separation of the ionic components to fonu essentially independent anions and cations, the electrolyte is tenued strong. By contrast, weak electrolytes, such as organic carboxylic acids, are present mainly in the undissociated fonu in solution, with the total ionic concentration orders of magnitude lower than the fonual concentration of the solute. Ionic conductivity will be treated in some detail below, but we initially concentrate on the equilibrium stmcture of liquids and ionic solutions. 

Organic Carboxylic Acids — (RCOOH) are usually weak acids but can be very corrosive to skin. However, The substitution of Cl atoms on the carbon next to the carboxylic carbon produces a stronger acid. Thus, trichloroacetic acid is almost a strong acid whereas acetic acid is a weak one. 

Organic Sulfonic Acids — (RSOjH) are generally stronger acids than organic carboxylic acids. 

Several processes act to increase soil acidity. As organic matter decays, it forms many organic carboxylic acids. Peat moss, for example, is entirely organic and has quite low pH, around 4. Acid rain, the result of... 

Chowhan, Z. T. pH-solubility profiles of organic carboxylic acids and their salts. 

Organic carboxylic acids are commonly found in foods, in the adipate process stream, and as pollutants. Fatty acids are the lipophilic portion of glycerides and a major component of the cell membrane. Phenols are widely used in polymers, as wood preservatives, and as disinfectants. Chloro-phenols such as 4-chlorophenol, two isomeric dichlorophenols, 2,4,6-tri-chlorophenol, three isomeric tetrachlorophenols, and pentachlorophenol were separated on a Dowex (The Dow Chemical Co. Midland, MI) 2-X8 anion exchange resin using an acetic acid-methanol gradient.138... 

Chowhan, Z. T., pH-solubility profiles of organic carboxylic acids and their salts, J. Pharm. Sci. 67, 1257-1260 (1978). 

An alpha hydroxy acid is an organic carboxylic acid in which an additional hydroxyl functional group (-OH) is present at the alpha position, i.e., on the carbon adjacent to the carboxyl functionality, -COOH. Figure 13.10.1 presents the struc-... 

Figure 8.1 Reaction scheme for the formation of a trimethysilyl ester between BSTFA and an organic carboxylic acid...

Ethylenediaminetetraacetic acid is frequently symbolized H4Y, and the disodium salt, Na2H2Y. The hydrogens in these formulas are the acidic hydrogens associated with the carboxyl groups, as in any weak organic carboxylic acid they dissociate from the EDTA ion in a series of equilibrium steps ... 

The complete conversion of glycerol with formation of dihydrogen and volatile organic carboxylic acids is an interesting feature of the system. The carboxylic acids could be isolated, if present in a significant amount, or further converted into H2 and CO2 by using an ad hoc bacterial strain. The photosynthetic bacterium Rhodospirillum ruhrum seems to be the most appropriate for such an application. A pH adjustment to 6 helps to improve the acid conversion with a very low residual organic acid content [36]. 

Dr L.Deffet, Bruxelles private communication, March 10,1954 Alkenyl Aromatics of the general formula Ar. CH, CHa. C CH2, were prepd by reacting aruEliatic nyuiocarbons (at moderate temp and press) with 1,3 diolefins in the presence of a catalyst(such as boron trihalide satd with an organic carboxylic acid). The purified alkenyl aromatics can be nitrated to yield expl derivs... 

In a broader sense, the term esterification may include all reactions in which esters, both of organic and inorganic acids, are formed. We shall limit the discussion in this section, however, to ester formation from organic carboxylic acids and alcohols... 

Solid Peroxygen Compounds. Hydrogen peroxide reacts with many compounds, such as borates, carbonates, pyrophosphates, sulfates, silicates, and a variety of organic carboxylic acids, esters, and anhydrides to give... 

In general the organic carboxylic acids will react with complete removal of alkoxides to form metal carboxylates. An important thermodynamic driving force here is the formation of the bidentate 02CR linkage (equation 62). This method represents a convenient route to carboxylates, and has been applied to a number of metals.237... 

Heating organic carboxylic acids may lead to decarboxylation (loss of C02). Using values available in Appendix 2A, calculate the temperature at which the decarboxylation of (a) formic acid, (b) acetic acid, and... 

Reactions 12-15 describe the standard neutralization reaction for an organic carboxylic acid. The discrepancy in neutralization capacity for the different reagents can be used to estimate the pK distribution [88]. Amounts between 50 and 500 /zeq acid per gram of carbon are characteristic values which indicate the high degree of experimental perfection required to determine such surface acidity data. Reactions 10 and 11 form derivatives of the carboxylic acid and can be used to volumetrically detect their presence by monitoring the gaseous reaction products. 

Photodecarboxylations of organic carboxylic acids are well known to occur via photoinduced electron transfer [90]. Although a large number of photodecarboxylations in the solution phase have been studied by using various acceptors such as aza aromatic compounds [91] and polycyanoaromatics [92], the product selec-tivities are necessarily low due to the co-occurrence of subsequent radical coupling because of the free motion of radical species in solution. In contrast, solid... 

Choice of solvent. The solvent cannot be selected on the basis of rules or theoretical considerations but must be experimentally determined. There are certain theoretical considerations which serve as a general guide for example, it is known that naphthalene, CioHs, is insoluble in water, H2O, but soluble in benzene, CeHe. From similar studies the general rule is drawn that a solid is best dissolved in a liquid which it resembles in chemical composition and structure. An organic carboxylic acid RCOOH is expected to dissolve in water since it contains the hydroxyl group, OH but if... 

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