4.2 Isomerism

What are isomers

compounds with same molecular formula but different structures.

what are the two types of isomers

structural isomers and stereo isomers

What are the three different structural isomers

positional isomers, chain isomers, functional group isomers

what is stereo isomerism

these are substances with same structural formula but who’s atoms/bonds take up different positions in space w

what are the two types of stereoisomers

geometric(E-Z) and optical

When does geometric isomerism occur

if there are 2 different types of atoms or group attached to same carbon atom of the double bond as there is no free rotation of that C=C double bond

What is an optical isomer

when a molecule and its mirror image are not superimposable.

when does an optical isomer occur

when there are 4 different substituents attached to one carbon atom which results in two isomers which are mirror images of one another but are not identical

what are optical isomers said to be

chiral meaning handed as in left or right hanged.the carbon atom which has the 4 different substituents attached to it is known as the chiral centre denoted with asterisk

example of optical isomer

normal light vs polarized light

what are optical isomers commonly called

enantiomers

how is optical rotation measured

using a polarimeter as enantiomers differ in the way they rotate the plane of polarized light

what would happen if plane polarized light is passed through two solutions each containing a different enantiomer of same substance

one will rotate the plane of polarized light clockwise and the other anti clockwise

definition os an enantiomer

an optical active isomer, with a chiral centre that will rotate the plane of polarized light

what does racemic mean

equal amounts