There is a problem with this question, because compound 1 has a higher melting point than compound 2.
Compound 1 has two isomers, that themselves have two different melting points (
For compound 2, the melting point is reported as
When we discuss melting point, we consider two main reasons:
- The intermolecular interactions.
- The packing in the solid.
As it could be seen from the given melting point, the trans-1,2-dichloroethene has the highest melting point because it has the largest surface area and therefor the molecules pack well in the solid which will result in a stronger intermolecular interactions that will result in higher melting point.