Question

Butanone is a four-carbon compound with a functional group.

• A. Carboxylic acid
• B. Aldehyde
• C. Ketone
• D. Alcohol

Answer 1

The correct option is C

Ketone

Explanation for correct option:

Option (C)

• A ketone is a functional group having a carbon atom attached to an oxygen atom with a double bond $\mathrm{C}=\mathrm{O}$ and other two valencies of carbon is satisfied by two alkyl groups.
• All the members of the ketone family are represented by the suffix ‘-One’
• Since Butaone has the suffix ‘One’ at the end, therefore it belongs to the ketone group.

Explanation for incorrect option.

a) Carboxylic acid ( -COOH) has the suffix ‘-Oic ’ at the end. All the members of the carboxylic group end with the suffix ‘-Oic ’. For examples Methanoic ( HCOOH), ethanoic (CH₃COOH), propanoic (CH₃CH₂COOH), and butanoic (CH₃CH₂CH₂COOH).

b) Aldehyde ( -CHO) has the suffix ‘-al ’ at the end. All the members of aldehyde end with the suffix ‘-al ’. For example Methanal (HCHO), ethanal (CH₃CHO), propanal (CH₃CH₂CHO) and butanal (CH₃CH₂CH₂COOH) Hence it cannot be correct.

d) Alcohol ( -OH) has the suffix ‘-ol ’ at the end. All the members of alcohol end with the suffix ‘-ol ’. For example Methanol (CH₃OH), ethanol (CH₃CH₂OH), propanol (CH₃CH₂CH₂OH) and butanol (CH₃CH₂CH₂CH₂OH). Hence it cannot be correct.

Hence, Butaone (CH₃CH₂COCH₃) has the suffix ‘One’ at the end, therefore it belongs to the ketone group. Therefore option (C) is correct.