Question

The correct structural formula of butanoic acid is

• A.

  

• B.

  

• C.

  

• D.

  

Answer 1

The correct option is D

The explanation for the correct option:

Option (d)

Butanoic acid:

• Butanoic acid (${\mathrm{C}}_4{\mathrm{H}}_8{\mathrm{O}}_2$) is a chemical compound that is greasy and colourless.
• It is a short-chain saturated fatty acid present in animal fats and plant oils as esters.
• Butanoic acid, commonly known as Butyric acid, is used to make butyrate esters.
• This molecule is also utilised in the production of Butyrate of Cellulose Acetate (CAB), which is employed in a variety of devices, components, and coatings and is more resistant to degradation than Cellulose Acetate.
• As the name suggests, Butanoic acid has four Carbon atoms, out of which one is Carbonyl Carbon as shown below:

The explanation for incorrect options:

Option (a)

• This option is incorrect as there is a double bond between two Carbons.
• Which makes it unsaturated, but Butanoic acid is a saturated compound.

Option (b)

• This option is also incorrect.
• Because there are five bonds on the carbonyl Carbon but carbon is tetravalent only.

Option (c)

• The given compound is an alcohol, as it has $-\mathrm{OH}$ functional group attached to it.
• But carboxylic acids must have $-\mathrm{COOH}$ groups attached to them.
• So this option is also incorrect.

So, the correct option is (d).