Question

Pyrolysis of ethyl acetate gives:
A. \[C{H_3}COC{H_3}\]
B. \[C{H_2} = C{H_2}\]
C. \[C{H_2} = C = O\]
D. \[C{H_3} - CHO\]

Answer 1

Hint: Pyrolysis is the thermal decomposition of a substance at a particular temperature in an inert atmosphere, it involves a change of chemical composition. On decomposition of ester carboxylic acid and ethylene are formed.

Complete step by step answer:
Pyrolysis of ethyl acetate \[\left( {C{H_3}COOC{H_2}C{H_3}} \right)\] gives ethane and acetic acid.
\[\mathop {\left( {C{H_3}COOC{H_2}C{H_3}} \right)}\limits_{\left( {ethyl{\text{ }}acetate} \right)} \xrightarrow[{Pyrolysis}]{\Delta }\mathop {C{H_3}COOH}\limits_{\left( {acetic{\text{ }}acid} \right)} + \mathop {C{H_2} = {\text{ }}C{H_2}}\limits_{\left( {ethylene} \right)} \]
Ethyl acetate is heated in the presence of liquid nitrogen and glass wool.
Pyrolysis reaction is converting esters containing a $\beta - $hydrogen atom into the corresponding carboxylic acid and alkene. The reaction is a unimolecular elimination and operates in a syn-elimination. The mechanism involves a unimolecular six – centered transition state producing equimolar ethylene and acetic acid.
Mechanism of pyrolysis of ethyl acetate


Therefore, the correct option is (D).

Note:
Ethyl acetate is a colorless liquid and is commonly known as ethyl ethanoate. Ethyl acetate is a polar aprotic solvent and it is a standard solvent. It is an important chemical compound. It is used especially for paints, varnishes, lacquers, cleaning and perfumes. The thermal decomposition of ethyl acetate follows a first order unimolecular reaction. The kinetic and thermodynamic parameters are obtained experimentally by applying the Arrhenius equation at a temperature range from $400^\circ $ to $600^\circ $C. The products from the pyrolysis of ethyl acetate were analyzed by gas chromatography.