Answer:
Option-B CH3−CH= CH−CH3
Explanation:
Isomers are defined as those compounds which have same molecular formula but structural formula. This means that isomers differ from each other only in connectivity patterns. Tho solve this problem we will find out the molecular formula of each given compound and then will compare to the reference compound.
Reference Compound:
CH2= CH− CH2−CH3
Molecular Formula = C₄H₈
Option-A:
CH3−CH3= CH3−CH3
Molecular Formula = C₄H₁₂
Option-B:
CH3−CH= CH−CH3
Molecular Formula = C₄H₈
Option-C:
CH3−CH2−CH2−CH3
Molecular Formula = C₄H₁₀
Option-D:
CH3−CH−CH2−CH3
Molecular Formula = C₄H₉
Result:
As it can be seen that Option-B has the same molecular formula as the reference compound. Hence, it is the correct answer.