Chapter 8, Problem 8.75P

Interpretation Introduction

Interpretation:

The possible geometric isomers of ${\text{C}}_{\text{2}}{\text{H}}_{\text{2}}{\text{Cl}}_{\text{2}}{\text{F}}_{\text{2}}$ has to be given.

Concept Introduction:

ISOMERS:

The molecules which have the same molecular formula but different arrangement of atom are called as isomers.  There are two types of isomers,

• Structural isomers
• Stereo isomers

Structural isomers:

A molecules with same chemical formulas but differ structurally in the sequence in which the atoms are linked are called as structural or constitutional isomers.

Stereo isomers:

Stereo isomers are the isomers that have same molecular formula but differ in spatial arrangement of atoms.  Stereo isomers can be sub divided into two groups,

• Optical isomers
• Geometric isomers

Optical isomers:

Optical isomers are the mirror image of a molecule and they can be rotated by plane polarized light.

Geometric isomers:

If there is restricted rotation in a molecule there arises geometric isomerism.  Geometric isomers are also known as Cis- Trans isomerism.

• If the two atoms locked in same side of the molecule then it is called as cis isomers.
• If the two atoms locked in opposite side of the molecule then it is called as trans isomers.