Question

Propanoic acid is greater than formic acid (methanoic acid) by:
(A) $C{H_2}$
(B) ${C_3}{H_6}$
(C) ${C_2}{H_4}$
(D) None of the above

Answer 1

In order to find how propanoic acid is greater than formic acid, we must be knowing about the chemical formula of both the chemical compounds. By subtracting the number of each element like carbon, hydrogen and oxygen we can find how propanoic acid is greater than formic acid.

Complete step by step answer:
The given organic chemical compound, i.e. formic acid and propanoic acid will come under the carboxylic acid group. First of all, what is a carboxylic acid? Carboxylic acid is a chemical compound which contains the Carboxyl group as the functional group. This carboxyl group will be attached to the R group which can be either alkyl group or aryl group.
Formic acid is also known as the Methanoic acid with the chemical formula of $HCOOH$. It will be having one carbon atom, two hydrogen atoms and two oxygen atoms.
The Propanoic acid is also known as propionic acid. The chemical formula of Propanoic acid is $C{H_3}C{H_2}COOH$. It will be having three Carbon atoms, six hydrogen atoms and two oxygen atoms.
The $C{H_3}C{H_2}COOH$ is greater from $HCOOH$ by two carbon atoms and four hydrogen atoms.
Therefore, Propanoic acid will be greater than Formic acid by ${C_2}{H_4}$.

Hence the correct answer is option (C) ${C_2}{H_4}$.

Note: Carboxylic acid can be prepared from different organic compounds such as
- It can be prepared by oxidation of primary alcohols and aldehydes.
- By hydrolysis of the nitriles.
- By hydrolysis of amides.
- It can be prepared from the ester. The hydrolysis of ester will give acids and alcohols.
- It can also be prepared from the Grignard reagent.