IMAT 2019 Q51 Chemistry

Have a question you need some help solving? Ask them here!
Please try to upload the questions in text format, if the question is a picture, try to transcribe it.
If you have problems uploading images, just go to, upload your pictures them embed them here!

The correct option is D.
You might be confusing with 2 that one actually the same compound so it can not be structural isomer. You can check this by naming the compound by IUPAC that is 2-methly pentane.
I am attaching the summary of the structural isomer that might be helpful for you.


Thank you so much. Could you also explain why 3 shows structural isomerism?

CH(OH)=CHCH2OH (Functional groups=> Alcohol and alkene)
Molecular formula: C3H6O2

CH3CH2COOH (Functional group=>carboxylic acid)
Molecular formular: C3H6O2

As both have same no of atoms and molecular formula and different structures so they are structural isomers.