[AStudent]

I am doing a review of gen. chem. in preparation for an ochem course, I will be taking this upcoming Fall semester. The problem I am struggling with asks me to draw out C₃H₆Cl₂. I saw 5 possibilities that can be viewed in the attached image. The answers in textbook, however, only showed II to V as possible molecules, not I. Why can't the 2 Cl atoms be placed at the ends of the Carbon chain?.

Thank you in advance for your time and assistance.

[AWK]

I = III

[Babcock_Hall]

One trick for deciding whether or not two drawings represent the same molecule is to name them using IUPAC's rules.