A – ethyl ethanoate
B – ethanol
C – sodium ethanoate
D – ethanoic acid
Esters upon alkaline hydrolysis gives back the carboxylic acid and the alcohol. The acid is initially obtained in its salt form. The reaction is called saponification.
CH3COOH2CH3 (ethyl ethanoate) \(\overset{NaOH}\longrightarrow\) CH3COONa (sodium ethanoate) + CH3CH2OH (ethanol)
The salt (sodium ethanoate) is treated with dil HCl to obtain the carboxylic acid.
CH3COONa (sodium ethanoate) + HCl → CH3COOH (ethanoic acid) + NaCl
Ethanol is oxidized to ethanoic acid in the presence of acidified potassium dichromate. Here, the acid used for acidification is H2SO4.
CH3CH2OH (ethanol) \(\overset{Acidified\,K_2Cr_2O_7}\longrightarrow\) CH3COOH (ethanoic acid)