Question

Write the IUPAC name of ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COOH}$.

• A. Ethyl formic acid
• B. Ethyl carboxylic acid
• C. Ethane methanoic acid
• D. Propionic acid

Answer 1

The correct option is D

Propionic acid

Explanation for the correct option:

Option (D): Propionic acid

• In this compound ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COOH}$, there are three carbon atoms present, so the root word is prop- and a functional group of acid is present. So, the IUPAC name is Propionic acid.

Therefore, the correct option is (D)

Explanation for the incorrect option:

Option (A) : The formic acid is a common name, not an IUPAC name apart from that there is three carbon but in this name, two carbon is only mentioned. So, Ethyl formic acid is an incorrect option.

Option (B): The compound contains three carbons but here the root word used is ethyl which means two carbon atoms. So ethyl carboxylic acid is an incorrect option.

Option (C): There is three carbon so the prop- prefix should be used but here it is split up as two (ethane) and one carbon (meth). So, Ethane methanoic acid is an incorrect option.

Hence, the correct option is (D), Propionic acid.