Question

Ethyl methyl ketone is obtained by heating calcium salts of

• A. formic acid $+$ propionic acid
• B. acetic acid $+$ propionic acid
• C. acetic acid only
• D. acetic acid $+$ methanoic acid

Answer 1

Answer: (B)

26. Ethyl methyl ketone is an unsymmetric ketone, so two different acids (in the form of calcium salt) are used. The structure of ethyl methyl ketone is

$C_2{H}_{5}COC{H}_3$

The structure shows the presence of 4 carbon atoms, thus the calcium salts must be of acetic acid and propionic acid to form $C_2{H}_{5}COC{H}_3$.

${\left(C_2{H}_{5}COO\right)}_{2}Ca+{\left(C{H}_{3}COO\right)}_{2}Ca\stackrel{\text{ Distill }}{⟶}$
$C_2{H}_{5}COC{H}_3+CaC{O}_3$