Question

Which of the following can be used for the preparation of propane?

• A. $C{H}_{3}CH\equiv C{H}_2\underset{\left(ii\right)AgN{O}_3/NaOH}{\overset{\left(i\right)B_2{H}_6}{\to }}$
• B. $C{H}_{3}C{H}_{2}C{H}_{2}Cl\underset{\left(ii\right)H_2{O}_2}{\overset{\left(i\right)Mg/ether}{\to }}$
• C. $C{H}_{3}C{H}_{2}C{H}_{2}I\stackrel{HI/{150}^{\circ }C}{\to }$
• D. $C{H}_{3}C{H}_{2}C{H}_{2}COONa\underset{△}{\overset{NaOH/CaO}{\to }}$

Answer 1

The correct option is D $C{H}_{3}C{H}_{2}C{H}_{2}COONa\underset{△}{\overset{NaOH/CaO}{\to }}$

The chemical formula for propane is $C{H}_{3}C{H}_{2}C{H}_3$.

Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide $C{O}_2$ from a compound.

Usually, decarboxylation refers to the reaction of carboxylic acids or their derivatives, removing a carbon atom from a carbon chain in the form of $C{O}_2$.

An alkane with one carbon atom less than the parent carbon chain will be formed in this process.

$C{H}_{3}C{H}_{2}C{H}_{2}COONa\underset{\Delta }{\overset{NaOH/CaO}{\to }}C{H}_{3}C{H}_{2}C{H}_3+N{a}_{2}C{O}_3$

The given reaction involves the removal of a carbon dioxide molecule, therefore, it is a decarboxylation reaction. Therefore, propane is formed by the decarboxylation of sodium propanoate

Hence, option (D) is correct.