Isomerism
Isomers share a molecular formula but differ in structure. Cambridge divides isomerism into structural isomerism (chain, positional and functional group) and stereoisomerism (geometrical and optical). These pages take each type in turn.
Revision Notes
3 revision notes, in the order the specification teaches them.
Geometric Isomerism
Restricted rotation about C=C, cis/trans and E/Z isomers, and identifying geometrical isomerism in alkenes and cyclic compounds (13.4.2, 13.4.3, 13.4.5).
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Structural Isomerism
Chain, positional and functional group isomerism, and deducing the possible isomers for a molecular formula (13.4.1, 13.4.6).
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Optical Isomerism
Chiral centres, enantiomers and identifying chiral centres in a given structural formula (13.4.2, 13.4.4, 13.4.5).
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Introduction to Organic Chemistry Map
Cambridge International AS & A Level Chemistry · Topic 13
The whole topic on one A4 page: formulae, homologous series and names, structural isomers and stereoisomers, shapes and hybridisation, bond breaking, reaction types and mechanisms, and the Cambridge AS table of functional groups.
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13.1.1
13.1.2
13.1.3
- 13.1.3
understand that the compounds in the table on pages 29 and 30 contain a functional group which dictates their physical and chemical properties
Revise
13.1.4
- a
interpret and use the general formulas of the classes of compound stated in the table on pages 29 and 30
Revise - b
interpret and use the structural formulas of the classes of compound stated in the table on pages 29 and 30
Revise - c
interpret and use the displayed formulas of the classes of compound stated in the table on pages 29 and 30
Revise - d
interpret and use the skeletal formulas of the classes of compound stated in the table on pages 29 and 30
Revise
13.1.5
- 13.1.5
understand and use systematic nomenclature of simple aliphatic organic molecules with functional groups detailed in the table on pages 29 and 30, up to six carbon atoms (six plus six for esters, straight chains only for esters and nitriles)
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13.1.6
13.2.1
- g i
interpret and use the term oxidation (in equations for organic redox reactions, the symbol [O] can be used to represent one atom of oxygen from an oxidising agent)
Revise - g ii
interpret and use the term reduction (in equations for organic redox reactions, the symbol [H] can be used to represent one atom of hydrogen from a reducing agent)
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13.2.2
- a
understand and use the terminology free-radical substitution associated with types of organic mechanisms
Revise - b
understand and use the terminology electrophilic addition associated with types of organic mechanisms
Revise - c
understand and use the terminology nucleophilic substitution associated with types of organic mechanisms
Revise - d
understand and use the terminology nucleophilic addition associated with types of organic mechanisms (in organic reaction mechanisms, the use of curly arrows to represent movement of electron pairs is expected; the arrow should begin at a bond or a lone pair of electrons)
Revise
13.3.1
13.3.2
- a
describe and explain the shape of, and bond angles in, molecules containing sp hybridised atoms
Revise - b
describe and explain the shape of, and bond angles in, molecules containing sp2 hybridised atoms
Revise - c
describe and explain the shape of, and bond angles in, molecules containing sp3 hybridised atoms
Revise
13.3.3
13.3.4
- 13.3.4
understand and use the term planar when describing the arrangement of atoms in organic molecules, for example ethene
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13.4.1
13.4.2
- b
describe geometrical (cis/trans) isomerism as a division of stereoisomerism (use of E/Z nomenclature is acceptable but is not required)
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13.4.3
- b
explain the origin of geometrical (cis/trans) isomerism in alkenes in terms of restricted rotation due to the presence of π bonds
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13.4.4
13.4.5
- b
identify geometrical (cis/trans) isomerism in a molecule of given structural formula including cyclic compounds
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13.4.6
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