Question

Sodium salt of acetic acid is converted into methane by
(A) dehydrogenation
(B) decarboxylation
(C) polymerization
(D) dehydration

Answer 1

Hint: An attempt to this question can be made by understanding the terms provided as options. An example will help you find resemblance to the reaction mentioned in the question. In the conversion of acetic acid to methane, the carboxylic acid group is released from the parent compound.

Complete Solution :
We will try to understand the processes mentioned in the options as suggested in the hint.
- Dehydrogenation refers to the removal of hydrogen from the organic compound. An example of this can be the conversion of alkane into alkene.
- Decarboxylation refers to the removal of the carboxylic functional group from the organic compound. An example of this can be conversion of propanoic acid to ethane.
- Polymerisation refers to the combination reaction between the reacting molecules to form long chains of compounds called polymers. The reacting molecules are called monomers. An example is the -polymerisation reaction of amino acids to produce the polymer proteins.
- Dehydration refers to the removal of water from the organic compound. An example of this can be conversion of alkanol into alkene by the release of water molecules.
- From the above statements we can conclude that sodium salt of acetic acid is converted into methane by decarboxylation reaction.
So, the correct answer is “Option B”.

Note: It is important to know that in a decarboxylation reaction, the product has once carbon less than the parent compound. This is because along with the alkane, carbon dioxide is released as a result of the removal of the carboxylic acid group.