Question

The secondary suffix, “-one” indicates the following functional group in the given compounds.

• A. $-\mathrm{COOH}$
• B.

  

• C.

  

• D. $-\mathrm{OH}$

Answer 1

The correct option is C

Explanation for the correct option:

(C)

• A functional group is a group of atoms attached to the hydrocarbon chains and it is responsible for providing distinct chemical and physical properties to the organic compounds.
• Secondary suffixes in organic compounds indicate the presence of a functional group. For example,$-\mathrm{OH}$ for alcohol, $-\mathrm{CHO}$ for aldehyde etc.
• A ketone functional group involves the presence of a carbonyl group$$\begin{gathered} \left(-\mathrm{C}- \\ \parallel \\ \mathrm{O}\right) \end{gathered}$$ and the carbon atom of this carbonyl group is bonded with two other carbon atoms of alkyl or aryl groups.

• In the given compound, the carbon atom of the carbonyl group must be bonded with two other carbon atoms of alkyl groups.
• Hence, the given compound has a ketone functional group.
• For the above-drawn structure, the secondary suffix “-one” must be used because the compound contains a ketone functional group.

Explanation for incorrect options:

(A)

• The secondary suffix “oic” is used for acid$\left(-\mathrm{COOH}\right)$.
• The general formula for acids is specified as $\mathrm{RCOOH}$.
• Examples of carboxylic acids functional groups are: Ethanoic acid$\left({\mathrm{CH}}_3\mathrm{COOH}\right)$, and propanoic acid$\left({\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COOH}\right)$.

(B)

• The secondary suffix “al” is used for aldehyde$\left(-\mathrm{CHO}\right)$.
• The general formula for aldehydes is specified as $\mathrm{R}-\mathrm{CHO}$.
• An example of aldehyde functional groups is Ethanal$\left({\mathrm{CH}}_3\mathrm{CHO}\right)$.

(D)

• The secondary suffix “ol” is used for alcohol$\left(-\mathrm{OH}\right)$.
• The general formula for alcohol is specified as $\mathrm{R}-\mathrm{OH}$.
• An example of an alcohol functional group is butanol$\left({\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_2\mathrm{OH}\right)$.

Hence, option (C) is correct. The secondary suffix “one” indicates the ketone functional group.