Geometrical Isomerism

Number of geometrical isomerism = 2^n, where n is the number of double bonds.

·         If n=1, then number of geometrical isomers is equal to 2(always).

·         If n>1, then number of geometrical isomers is less than or equal to 2ⁿ.

If numbering can be started from either of the two sides then number of geometrical isomers is less than 4.

If numbering can be started from only one side then number of geometrical isomers is equal to four.

Properties : -

1. Stability of Goemetrical Isomers :- Generally, trans is more stable than cis because cis isomer is more sterically crowded than trans. 

                      trans > cis          (Stability)

2. Melting Point :- It is directly proportional to van der Wall's intermolecular forces and this force is directly   proportional  to polarisibility and surface area.

Since trans has more surface area than cis trans will have higher melting point than cis.  

                       trans > cis           (m.p)

                                         

3. Solubility :- It is inversely proportional to van der Walls intermolecular force.So, cis will have more         solubility than trans.

                        cis > trans            (Solubility)