Question

Identify the following pairs of structures as structural isomers, cis-trans isomers, or the same molecule:

Short answer

Part(a) The pair is structural isomers

Part(b) The pair is cis-trans isomers

Step-by-step solution

Part(a) Step 1 : Given information

We need to classify the pairs of structures as structural isomers, cis-trans isomers, or the same molecule

Part(a) Step 2 : Simplify

We can clearly see in first structure Chloro group is at $C_1$but in second structure it is at $C_3$carbon, according to IUPAC rules.

Hence,

The pair is structural isomers

Part(b) Step 1 : Given information

We need to classify the pairs of structures as structural isomers, cis-trans isomers, or the same molecule

Part(b) Step 2 : Simplify

We can clearly see that the structures are similar except their orientation. in first $C{H}_3$and $H$ are on same side but in second structure, they are opposite to each other.

Therefore,

The pair is cis-trans isomers