Aqa optical isomerisms
Revision allergy chemistry
Optical isomerism is a form of stereo isomerisms and occurs as a
result of chirality in molecules, limited to molecules with a single
chiral centre
An asymmetric carbon atom is chiral and gives rise to optical
isomerisms (enantiomers), which can exist as non
superimposable mirror images and differ in their effect on plane
polarised light.
A mixture of equal amounts of enantiomers is called a racemic
mixture
Students should be able to:
-Draw the structural formulas and displayed formulas of
enantiomers
-Understand how racemic mixtures are formed and why they are
optically inactive
Opical isomers
Optical isomerism is a form of stereoisomerism, they have the same
structural formula but different arrangement of atoms in space. Optical
isomers are mirror images of each other and have chiral carbons. Chiral
molecules have 4 different groups in 2 different ways which forms two
different molecules. These are called enantiomers. These enantiomers are
mirror images of each other and are non-superimposable. No matter
which way you turn them they will not overlap.
Finding a chiral centre
First we need to find the chiral centre then draw them in a tetrahedral 3D
shape to show them as enantiomers. We need to find the carbon atom
with 4 different groups surrounding it. Then we need to draw this using
the tetrahedral 3D shape. Then we draw the mirror image to show both
enantiomers, draw the mirror line to help you.
Plane polarised light
Optically active isomers will rotate plane polarised light. This method of
detecting an optically active compound. Standard light oscillates in all
directions. We pass the light through the polarised filter to produce plain
polarised light. This light only oscillates n one direction. Optically active
Revision allergy chemistry
Optical isomerism is a form of stereo isomerisms and occurs as a
result of chirality in molecules, limited to molecules with a single
chiral centre
An asymmetric carbon atom is chiral and gives rise to optical
isomerisms (enantiomers), which can exist as non
superimposable mirror images and differ in their effect on plane
polarised light.
A mixture of equal amounts of enantiomers is called a racemic
mixture
Students should be able to:
-Draw the structural formulas and displayed formulas of
enantiomers
-Understand how racemic mixtures are formed and why they are
optically inactive
Opical isomers
Optical isomerism is a form of stereoisomerism, they have the same
structural formula but different arrangement of atoms in space. Optical
isomers are mirror images of each other and have chiral carbons. Chiral
molecules have 4 different groups in 2 different ways which forms two
different molecules. These are called enantiomers. These enantiomers are
mirror images of each other and are non-superimposable. No matter
which way you turn them they will not overlap.
Finding a chiral centre
First we need to find the chiral centre then draw them in a tetrahedral 3D
shape to show them as enantiomers. We need to find the carbon atom
with 4 different groups surrounding it. Then we need to draw this using
the tetrahedral 3D shape. Then we draw the mirror image to show both
enantiomers, draw the mirror line to help you.
Plane polarised light
Optically active isomers will rotate plane polarised light. This method of
detecting an optically active compound. Standard light oscillates in all
directions. We pass the light through the polarised filter to produce plain
polarised light. This light only oscillates n one direction. Optically active
