Chemistry - STRUCTURAL ISOMERISM Question with Solution | TestHub

(A) n-butane and 2-methylpropane are both ${\mathrm{C}}_4{\mathrm{H}}_{10}$ ✓ isomers. (B) acetaldehyde and cyclopropanol are both ${\mathrm{C}}_3{\mathrm{H}}_6\mathrm{O}$ ✓ isomers. (D) methyl acetate and prop-1-ene-1,3-diol are both ${\mathrm{C}}_3{\mathrm{H}}_6{\mathrm{O}}_2$ ✓ isomers. In (C), 1-methylcyclobutene is ${\mathrm{C}}_5{\mathrm{H}}_8$ while but-1-yne is ${\mathrm{C}}_4{\mathrm{H}}_6$ - different molecular formulas, so they are NOT structural isomers.