Topic 18
Organic
Chemistry III
Topic 18 Organic Chemistry III has three parts. Topic 18A, arenes, covers the structure and reactions of benzene and phenol. Topic 18B covers amines, amides, amino acids and proteins. Topic 18C, organic synthesis, pulls the course together: deducing formulae from combustion analysis, percentage composition, characteristic reactions and spectra, planning reaction schemes of up to four steps, Grignard reagents, selecting and justifying procedures and control measures, and the techniques used to prepare and purify organic compounds.
Revision Notes
23 revision notes, in the order the specification teaches them.
Structure and Bonding in Benzene
The structure and bonding of benzene: the Kekulé and delocalised models, p-orbital overlap, the π system and how benzene is represented.
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Evidence for the Structure of Benzene
The evidence for the structure of benzene: hydrogenation enthalpies, delocalisation energy, bond lengths and resistance to addition.
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Electrophilic Substitution in Benzene
Electrophilic substitution in benzene: substitution versus addition, the general mechanism and the delocalised intermediate.
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Nitration of Benzene
The nitration of benzene: reagents and conditions, generation of NO₂⁺, the mechanism and the role of sulfuric acid.
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Halogenation of Benzene
The halogenation of benzene: the catalyst, generation of the halogen electrophile and the electrophilic substitution mechanism.
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Friedel–Crafts Alkylation and Acylation
Friedel–Crafts alkylation and acylation of benzene: AlCl₃ catalyst, the electrophile and the mechanism.
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Other Reactions of Benzene
The combustion of benzene, with a reaction map of the arene chemistry.
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Phenol and Bromine Water
Phenol: the activated ring, bromination to 2,4,6-tribromophenol, compared with benzene.
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Amines, Amides and Amino Acids: Structure and Naming
The structure and naming of amines, amides and amino acids: classification, nomenclature, formulae and physical properties.
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Preparing Amines
Preparing amines: halogenoalkanes with ammonia, reduction of nitriles, and the reduction of nitrobenzene to phenylamine with tin and concentrated hydrochloric acid.
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Amines as Bases
Amines as bases: the nitrogen lone pair, alkaline solutions, salt formation with acids and the order of base strength of ammonia, aliphatic and aromatic amines.
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Amines as Nucleophiles
Amines as nucleophiles: substitution with halogenoalkanes and the formation of N-substituted amides with acyl chlorides.
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Amides
Amides: structure, naming, preparation from acyl chlorides and the amide link.
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Amino Acids and Zwitterions
Amino acids: zwitterions, acid and base behaviour, the isoelectric point and chirality.
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Peptides and Proteins
Peptides and proteins: the peptide link, dipeptides and tripeptides, hydrolysis and proteins as polymers of amino acids.
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Condensation Polymers: Polyamides and Polyesters
Condensation polymers: polyamides and polyesters, repeat units, monomers, linkages and intermolecular forces.
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Deducing Formulae from Analytical Data
Deducing empirical, molecular and structural formulae from combustion analysis, percentage composition and spectra.
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Identifying Functional Groups by Chemical Tests
Identifying functional groups by chemical tests and predicting the properties and reactions of unfamiliar compounds.
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Grignard Reagents and Carbon–Carbon Bond Formation
Forming carbon–carbon bonds in synthesis: Grignard reagents with carbon dioxide and carbonyl compounds, and the nitrile route.
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Planning a Synthetic Route
Planning multi-step organic synthesis routes: the reaction map, working backwards from the target.
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Choosing Procedures and Managing Hazards
Selecting and justifying practical procedures for organic reactions and choosing control measures from hazard data.
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Preparing and Purifying Organic Solids
Preparing and purifying organic solids: reflux, filtration, recrystallisation, drying and melting temperature determination.
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Purifying Liquids: Distillation, Steam Distillation and Solvent Extraction
Purifying organic liquids: distillation, steam distillation, solvent extraction, drying and checking purity.
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Summary maps
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Benzene Map
Edexcel A Level Chemistry · Topic 18A Arenes
Every reaction on one A4 page: reagents, conditions and reaction type for each arrow, colour coded, with the key tests.
Amines Map
Edexcel A Level Chemistry · Topic 18B Amines, amides, amino acids and proteins
Every reaction on one A4 page: reagents, conditions and reaction type for each arrow, colour coded, with the key tests.
Nitriles Map
Edexcel A Level Chemistry · Topics 17C and 18B
Every reaction on one A4 page: reagents, conditions and reaction type for each arrow, colour coded, with the key tests.
Amino Acids Map
Edexcel A Level Chemistry · Topic 18B Amines, amides, amino acids and proteins
Every reaction on one A4 page: reagents, conditions and reaction type for each arrow, colour coded, with the key tests.
Grignard Reagents Map
Edexcel A Level Chemistry · Topic 18C Organic synthesis
Every reaction on one A4 page: reagents, conditions and reaction type for each arrow, colour coded, with the key tests.
Benzene Structure Map
Edexcel A Level Chemistry · Topic 18A Benzene Structure and Stability
The whole section on one A4 page: the Kekulé and delocalised models, bond lengths, hydrogenation, bromine water and isomers.
Substitution and Phenol Map
Edexcel A Level Chemistry · Topic 18A Electrophilic Substitution and Phenol
The whole section on one A4 page: the mechanism, nitration, halogenation, Friedel-Crafts reactions, combustion and phenol.
Amines and Polymers Map
Edexcel A Level Chemistry · Topic 18B Amines, Amides and Polymers
All of the amines, amides and polymers lessons on one A4 page: classes, routes to amines, bases, nucleophiles, copper(II) ions, polyamides and polyesters.
Amino Acids and Proteins Map
Edexcel A Level Chemistry · Topic 18B Amino Acids and Proteins
Amino acids and proteins on one A4 page: zwitterions, enantiomers, the polarimeter, peptides, hydrolysis and chromatography.
Formulae and Structures Map
Edexcel A Level Chemistry · Topic 18C
Formulae from analysis, chemical tests and combined spectra on one A4 page.
Grignard and Routes Map
Edexcel A Level Chemistry · Topic 18C
Grignard reagents, aliphatic and aromatic routes, and planning a synthesis on one A4 page.
Practical Techniques Map
Edexcel A Level Chemistry · Topic 18C
Reflux, distillation, purifying liquids and solids, aspirin and hazards on one A4 page.
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Specification
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18
- A.2 a
understand that enthalpy changes of hydrogenation provide evidence for the delocalised model of benzene
Revise - A.2 b
understand that carbon-carbon bond lengths provide evidence for the delocalised model of benzene
Revise - A.3 a
understand why benzene is resistant to bromination compared with alkenes due to delocalisation in benzene
Revise - A.3 b
understand why alkenes are more reactive to bromination due to localised electron density in the π-bond
Revise - A.4iii
understand the reactions of benzene with: a mixture of concentrated nitric and sulfuric acids
Revise - A.4iv a
understand the reactions of benzene with halogenoalkanes using aluminium chloride catalyst in Friedel-Crafts alkylation
Revise - A.4iv b
understand the reactions of benzene with acyl chlorides using aluminium chloride catalyst in Friedel-Crafts acylation
Revise - A.5 a
understand the mechanism of electrophilic substitution in halogenation of benzene including generation of the electrophile
Revise - A.5 b
understand the mechanism of electrophilic substitution in nitration of benzene including generation of the electrophile
Revise - A.5 c
understand the mechanism of electrophilic substitution in Friedel-Crafts reactions of benzene including generation of the electrophile
Revise - B.9i
understand the reactions of primary aliphatic amines, using butylamine as an example, with: water to form an alkaline solution
Revise - B.9ii
understand the reactions of primary aliphatic amines, using butylamine as an example, with: acids to form salts
Revise - B.9iii
understand the reactions of primary aliphatic amines, using butylamine as an example, with: ethanoyl chloride
Revise - B.9iv
understand the reactions of primary aliphatic amines, using butylamine as an example, with: halogenoalkanes
Revise - B.9v
understand the reactions of primary aliphatic amines, using butylamine as an example, with: copper(II) ions to form complex ions
Revise - B.10 d
understand reasons for differences in basicity between ammonia, primary aliphatic amines and primary aromatic amines given suitable data
Revise - B.11i
understand, in terms of reagents and general reaction conditions, the preparation of primary aliphatic amines: from halogenoalkanes
Revise - B.11ii
understand, in terms of reagents and general reaction conditions, the preparation of primary aliphatic amines: by the reduction of nitriles
Revise - B.12
know that aromatic nitro-compounds can be reduced, using tin and concentrated hydrochloric acid, to form amines
Revise - B.15i
be able to draw the structural formulae of the repeat units of condensation polymers formed by reactions between: dicarboxylic acids and diols
Revise - B.15ii
be able to draw the structural formulae of the repeat units of condensation polymers formed by reactions between: dicarboxylic acids and diamines
Revise - B.15iii
be able to draw the structural formulae of the repeat units of condensation polymers formed by reactions between: amino acids
Revise - B.16i
understand the properties of 2-amino acids, including: acidity and basicity in solution, as a result of the formation of zwitterions
Revise - B.16ii
understand the properties of 2-amino acids, including: effect of aqueous solutions on plane-polarised monochromatic light
Revise - B.17i
understand that the peptide bond in proteins: is formed when amino acids combine, by condensation polymerisation
Revise - B.17ii
understand that the peptide bond in proteins: can be hydrolysed to form the constituent amino acids, which can be separated by chromatography
Revise - C.18 g
be able to deduce structural formulae from characteristic reactions of functional groups
Revise - C.21 a
be able to select suitable practical procedures for reactions involving specified functional groups
Revise - C.21 b
be able to justify suitable practical procedures for reactions involving specified functional groups
Revise - C.22i
understand the following techniques used in the preparation and purification of organic compounds: refluxing
Revise - C.22ii
understand the following techniques used in the preparation and purification of organic compounds: purification by washing
Revise - C.22iii
understand the following techniques used in the preparation and purification of organic compounds: solvent extraction
Revise - C.22iv
understand the following techniques used in the preparation and purification of organic compounds: recrystallisation
Revise - C.22v
understand the following techniques used in the preparation and purification of organic compounds: drying
Revise - C.22vi b
understand steam distillation as a preparation/purification technique for organic compounds
Revise - C.22vii
understand the following techniques used in the preparation and purification of organic compounds: melting temperature determination
Revise - C.22viii
understand the following techniques used in the preparation and purification of organic compounds: boiling temperature determination
Revise
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