Question

Which one of the following is mixed ketone?
A.

B.

C.

D.

Answer 1

Hint: Ketone is a carbonyl compound whose carbonyl group is placed between two hydrocarbons that are aliphatic alkyl groups or aromatic alkyl groups. General formula of Ketone \[{R_1}CO{R_2}\] where ${R_1}$ and ${R_2}$ are alkyl groups.

Complete step by step answer:
We know that the general formula of Ketone is \[{R_1}CO{R_2}\] where ${R_1}$ and ${R_2}$ can either be an alkyl group or aryl group. There are some important terms that should be known specifically such as simple ketone, aromatic ketone and mixed ketone. Simple ketone is a type of ketone whose ${R_1}$ and ${R_2}$ both are an alkyl group. Aromatic ketone refers to those ketone whose ${R_1}$ and ${R_2}$ are aryl groups. Mixed Ketone can be defined as ketone whose ${{R}_{1}}$ is an alkyl group and ${{R}_{2}}$ is an aryl group or vice versa.

OPTION A: By looking into option A we can make out that it is a simple ketone as ${{R}_{1}}$ and ${{R}_{2}}$ attached to carbonyl carbon are of alkyl groups. Therefore it is a simple ketone.

OPTION B: From option B we can tell it is also a simple ketone whose ${{R}_{1}}$ is an ethyl group and ${{R}_{2}}$ methyl group. Therefore it is also a simple ketone.

OPTION C: The ${{R}_{1}}$ and ${{R}_{2}}$ are ${C_6}{H_5}$ (aromatic) and $C{H_3}$ (aliphatic) respectively of the given compound. Here one is an aryl group and the other is an alkyl group therefore it satisfies the definition of mixed ketone as mentioned above, Hence it is a mixed ketone.

OPTION D: Both the ${{R}_{1}}$ and ${{R}_{2}}$ of ketone are aryl groups. This meets the definition of aromatic ketone as mentioned above, therefore it is an aromatic ketone.
Conclusion that we can draw from the above discussion is that only option C exactly meets the definition of mixed ketone. So, the correct answer is “Option C”.

Note: In a mixed ketone the ${{R}_{1}}$ and ${{R}_{2}}$ not be of same kind that is both should not be of alkyl groups or aryl groups. If ${{R}_{1}}$ is an alkyl group then ${{R}_{2}}$ should be of the aryl group or vice versa then it satisfies the definition of mixed ketone.