Question

Write chemical equation for two methods of preparation and three chemical properties of carboxylic acid.

Hint:

Carboxylic acids are weak acids but stronger than alcohols; they easily form esters and undergo decarboxylation on heating with soda lime.

Answer 1

Methods of Preparation:
1. Oxidation of primary alcohols/aldehydes:
\[ RCH_2OH \xrightarrow{[O]} RCOOH ; RCHO \xrightarrow{[O]} RCOOH \]
2. Hydrolysis of nitriles:
\[ RCN + 2H_2O \xrightarrow{H^+/OH^-} RCOOH + NH_3 \]
--- Chemical Properties:
1. Acidic nature:
\[ RCOOH \rightleftharpoons RCOO^- + H^+ \]
2. Reaction with alcohols (esterification):
\[ RCOOH + R'OH \xrightarrow{H^+} RCOOR' + H_2O \]
3. Decarboxylation:
\[ RCOONa + NaOH \xrightarrow{CaO, \Delta} RH + Na_2CO_3 \]
Thus, carboxylic acids are prepared by oxidation and hydrolysis, and show acidic, esterification, and decarboxylation reactions.