why are trans isomers...?

Question

why are trans isomers more stable than cis isomers?

Answer 1

Trans- isomers are more stable than cis- isomers because they keep similar groups farther apart. For example, trans- and cis- dichloro-ethene:

Trans- vs. Cis- dichloroethene:
trans:
http://shrimpandgrits.rickandpatty.com/blogfiles/transdce.png
cis:
http://shrimpandgrits.rickandpatty.com/blogfiles/cisdce.png

Obviously, in trans, the two Cl's are farther apart. The story of stability in chemistry and materials is that alike things don't like to be by each other (like 2 positive charges or 2 magnetic norths repeling each other). In organics, like groups close to each other experience what's called steric interactions, which make a molecule more unstable than the two alike groups being as far away as possible.

Answer 2

you can get its answer from "isomers in transformers"!!!!!!!!!!!!!!