Question

The name of the compound ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{CHO}$ is

• A. Propanal
• B. Propanone
• C. Ethanol
• D. Ethanal

Answer 1

The correct option is A

Propanal

The explanation for correct option

(A)Propanal

IUPAC name of ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{CHO}$

• Determination of Root Word : Select the continuous chain with the maximum number of carbon atoms. Here the chain is having three carbon atoms, hence root word will be “Prop".
• Determination of names and positions of Locants:-There is no substituent at the given compound.
• Determination of Suffix :-The functional group present is an aldehyde $\left(\mathrm{CHO}\right)$. Hence the suffix is ‘-al’.
• So, the IUPAC name of ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{CHO}$ is propanal.

Explanation for incorrect option

• The formula of propanone is ${\mathrm{CH}}_3{\mathrm{COCH}}_3$.
• The formula of ethanol is ${\mathrm{CH}}_3-{\mathrm{CH}}_2\mathrm{OH}$.
• The formula of ethanal is ${\mathrm{CH}}_3\mathrm{CHO}$.
• Hence, the options (B), (C), and (D) are incorrect.

Hence, option (A) is correct. The IUPAC name of ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{CHO}$ is propanal.