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The conversion between hydroxyl value and other hydroxyl content measurements is obtained by multiplying the hydroxyl value by the factor 17/560. [2] The chemical substance may be a fat, oil, natural or synthetic ester, or other polyol. [3] ASTM D 1957 [4] and ASTM E222-10 [5] describe several versions of this method of determining hydroxyl value.
For example, acetic acid is a weak acid which has a = 1.75 x 10 −5. Its conjugate base is the acetate ion with K b = 10 −14 / K a = 5.7 x 10 −10 (from the relationship K a × K b = 10 −14 ), which certainly does not correspond to a strong base.
Acetic acid / ə ˈ s iː t ɪ k /, systematically named ethanoic acid / ˌ ɛ θ ə ˈ n oʊ ɪ k /, is an acidic, colourless liquid and organic compound with the chemical formula CH 3 COOH (also written as CH 3 CO 2 H, C 2 H 4 O 2, or HC 2 H 3 O 2). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component of vinegar ...
On heating, the di-ester undergoes thermal decarboxylation, yielding an acetic acid substituted by the appropriate R group. [1] Thus, the malonic ester can be thought of being equivalent to the − CH 2 COOH synthon. The esters chosen are usually the same as the base used, i.e. ethyl esters with sodium ethoxide.
Over time, the acidity of the acetic acid and tannins in an aging wine will catalytically protonate other organic acids (including acetic acid itself), encouraging ethanol to react as a nucleophile. As a result, ethyl acetate—the ester of ethanol and acetic acid—is the most abundant ester in wines. Other combinations of organic alcohols ...
The chemist Urech in 1872 was the first to synthesize cyanohydrins from ketones with alkali cyanides and acetic acid [2] and therefore this reaction also goes by the name of Urech cyanohydrin method. References
Another test relies on reaction of the furfural with phloroglucinol to produce a colored compound with high molar absorptivity. [4] It also gives a positive test with hydrazines, hydrazones, α-hydroxy ketones and 1,2-dicarbonyls. Both Tollens' reagent and Fehling's reagent give positive results with formic acid. [citation needed]
The technically most significant use of ethenone is the synthesis of sorbic acid by reaction with 2-butenal (crotonaldehyde) in toluene at about 50 °C in the presence of zinc salts of long-chain carboxylic acids. This produces a polyester of 3-hydroxy-4-hexenoic acid, which is thermally [22] or hydrolytically depolymerized to sorbic acid.