Which acid has the most basicity

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Acidity and Basicity of Carboxylic Acids

Carboxylic acids (values ​​from 3 to 6) are much stronger acids than alcohols (values ​​from 15 to 17) and as aldehydes or ketones (values ​​from 14 to 20). They therefore react with bases such as NaOH and NaHCO3 to the carboxylate salt,. Carboxylic acids with more than six carbon atoms are only sparingly soluble in water, while all alkali salts of carboxylic acids are readily soluble in water because they are ions.

Like other Brønsted acids, carboxylic acids dissociate in aqueous solutions to give H.3O+ and carboxylate ions, RCO2-. The degree of dissociation is described by the acid constant.

Most carboxylic acids have a value of around 10-5 . For example, acetic acid has a 1.76 x 10-5 which corresponds to a value of 4.75. In practice, values ​​around 5 mean that approx. 0.1 percent of the molecules in a 0.1 molar solution are dissociated. For comparison: In the case of the strong acid HCl with a value of -7, 100 percent of all molecules in such a solution are dissociated. The value of ethanol is around 10-16 , i.e. that ethanol has an approx. 1011- times weaker acid than acetic acid.

Carboxylic acids are more acidic than alcohols because in the carboxylate - in contrast to the alcoholate ion - the negative charge can be distributed to two oxygen atoms by mesomerism.

Exercise: acidity and basicity of carboxylic acids