Hello!
Option B is a structural isomer of butanol.
Why?
A structural isomer is a molecule that has the same molecular formula, but a different structural arrangement of atoms.
Knowing that the molecular formula of Butanol is C₄H₁₀O, let's look at the different options:
A) This compound is called Butane, and its molecular formula is C₄H₁₀-Not an structural isomer of Butanol.
B) This compound is called Butan-2-ol, and its molecular formula is C₄H₁₀O-It is an structural isomer of Butanol. The only difference is the location of the -OH group.
C) This compound is called Ethyl Methyl Ether, and its molecular formula is C₃H₈O-Not an structural isomer of Butanol.
D) This compound is called Butanal, and its molecular formula is C₄H₈O-Not an structural isomer of Butanol.
Have a nice day!