The isomer of hexanoic acid D) Methylbutanoic acid . Therefore , D) Methylbutanoic is correct.
Hexanoic acid, also known as caproic acid, has a molecular formula of C6H12O2.
It belongs to the class of carboxylic acids and is a six-carbon linear chain with a carboxyl group (COOH) at one end.
Methylbutanoic acid is an isomer of hexanoic acid with the same molecular formula (C6H12O2).
The structure of methylbutanoic acid involves a five-carbon chain with a methyl group (CH3) attached to the fourth carbon, and the carboxyl group is situated at the end of the chain.
This structural arrangement gives it the IUPAC name 2-methylbutanoic acid.
On the other hand, the options A) penthylformiate, B) izopropyleacetate, and C) methylpropanoate do not represent isomers of hexanoic acid.
Penthylformiate seems to contain a misspelling ("penthyl" instead of "pentyl"), izopropyleacetate contains a misspelling ("izopropyl" instead of "isopropyl").
The methylpropanoate is a different compound with a three-carbon chain.