What type of isomerism occurs when molecules differ in their effect on plane-polarised light?
Optical isomerism
This occurs due to chirality in molecules.
What type of carbon atom causes optical isomerism in organic molecules?
Chiral carbon
A carbon bonded to four different groups.
Fill in the blank:
A carbon atom attached to four different groups is called an _______ carbon.
asymmetric
This type of carbon atom is also described as chiral.
True or False:
Optical isomerism is a form of stereoisomerism.
True
The molecules have the same structural formula but differ in spatial arrangement.
What name is given to optical isomers that are non-superimposable mirror images?
Enantiomers
They rotate plane-polarised light in opposite directions.
True or False:
Enantiomers have identical physical properties except for their interaction with plane-polarised light.
True
They may also behave differently in biological systems.
Fill in the blank:
Optical isomers differ in the direction they rotate _______ polarised light.
plane
One rotates light clockwise and the other anticlockwise.
What is a mixture containing equal amounts of two enantiomers called?
Racemic mixture
Also known as a racemate.
True or False:
A racemic mixture rotates plane-polarised light.
False
Equal and opposite rotations cancel each other out.
Fill in the blank:
A racemic mixture is optically _______.
inactive
The effects of the two enantiomers cancel out.
Why are enantiomers described as non-superimposable mirror images?
Different spatial arrangement
The molecules cannot be aligned exactly even when mirrored - they are non superimposable mirror images of one another
What property of a molecule leads to optical isomerism?
Chirality
A chiral molecule lacks a plane of symmetry and has a chiral centre.
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3.1.1 Atomic structure50
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3.1.2 Amount of substance47
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3.1.3 Bonding90
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3.1.4 Energetics62
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3.1.5 Kinetics55
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3.1.6 Equilibria & Kc24
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3.1.7 Redox equations17
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3.1.8 Thermodynamics27
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3.1.9 Rate equations24
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3.1.10 Kp12
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3.1.11 Electrode potentials46
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3.1.12 Acids and bases69
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3.2.1 Periodicity22
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3.2.2 Group 2 metals24
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3.2.3 Group 7 (halogens)31
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3.2.4 Period 3 oxides35
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3.2.5 Transition metals95
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3.2.6 Ions in aqueous solution39
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3.3.1 Intro to organic chemistry42
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3.3.2 Alkanes49
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3.3.3 Halogenoalkanes36
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3.3.4 Alkenes36
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3.3.5 Alcohols43
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3.3.6 Organic analysis36
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3.3.7 Optical isomerism12
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3.3.8 Aldehydes & ketones20
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3.3.9 Carboxylic acids & derivatives25
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3.3.10 Aromatic chemistry29
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3.3.11 Amines41
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3.3.12 Polymers24
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3.3.13 Amino acids, proteins, DNA61
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3.3.14 Organic synthesis12
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3.3.15 NMR spectroscopy14
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3.3.16 Chromatography12
