Question

How ethanoic acid can be prepared by ethanol and ethanenitrile?

Answer 1

Ethanol is an alcohol and ethanoic acid a carboxylic acid. And we know that alcohols can be converted to carboxylic acids by oxidation in the presence of strong oxidizing agents. Ethanol can be converted to ethanenitrile by simple hydrolysis reaction, in the presence of dilute acid or alkali.

Complete step-by-step answer: Ethanol can be converted to ethanoic acid by the process of oxidation. Oxidation refers to the process of loss of electrons by an atom. For oxidation to occur we use oxidizing agents.
The steps followed in the conversion are described as follows:
The primary alcohol (ethanol) is oxidized to an aldehyde (ethanal). Then, ethanal is further oxidized and forms carboxylic acid (ethanoic acid).
The nascent oxygen is obtained from the oxidizing agent used during the reaction, which helps in the oxidation. The reaction takes place as depicted below.
$\begin{aligned} & C{{H}_{3}}C{{H}_{2}}OH+\,\left[ O \right]\to C{{H}_{3}}CHO\,+{{H}_{2}}O \\\ & C{{H}_{3}}CHO+\left[ O \right]\to C{{H}_{3}}COOH \\\ \end{aligned}$
The oxidizing agents used are $KMn{{O}_{4}}/{{H}^{+}},\,{{K}_{2}}C{{r}_{2}}{{O}_{7}}/{{H}^{+}}$etc.
Now, let’s see how ethanenitrile can be converted to ethanoic acid
This conversion can be achieved by the complete hydrolysis of ethanenitrile with dilute mineral acid or caustic alkali to yield carboxylic acid (ethanoic acid).
The reaction is represented as follows:
$C{{H}_{3}}C\equiv N+\,dil\,HCl\to \,C{{H}_{3}}COOH$

Note: It should be noted that for the conversion of ethanol to ethanenitrile we should always use strong oxidizing reagents like jones reagent. If we use weak oxidizing agents like PCC then the reaction will stop at the aldehyde stage and as a result desired product of ethanoic acid will not be formed.