Organic chemistry – A Level AQA Chemistry revision notes

What this topic covers

Organic chemistry has 16 subtopics, including:

• Introduction to organic chemistry
• Alkanes
• Halogenoalkanes
• Alkenes
• Alcohols
• Organic analysis

Organic chemistry lessons by subtopic

81 lessons, grouped by subtopic.

Introduction to organic chemistry

• Understanding Reaction Mechanisms: An introduction to reaction mechanisms, focusing on their importance in organic chemistry and the representation of radicals.
• Curly Arrows: Bond Formation and Breaking: Learn how to use curly arrows to represent the formation and breaking of covalent bonds in reaction mechanisms.
• Exploring Free-Radical Mechanisms: An overview of free-radical mechanisms, including writing balanced equations and understanding the representation of electron movement (note: curly arrows are not required).
• Formulae in Organic Chemistry: Learn about empirical, molecular, general, structural, displayed and skeletal formulas and how organic compounds can be represented.
• IUPAC Nomenclature and Homologous Series: Understand IUPAC rules for naming and drawing organic compounds with up to six carbon atoms in chains and rings. Explore the characteristics of homologous series.
• Structural Isomerism: Types and Drawing: Learn about structural isomers, including chain, position, and functional group isomers, and practice drawing their structures.
• Stereoisomerism and E-Z Isomers: Explore stereoisomerism and E-Z isomers, understanding their formation due to restricted rotation around double bonds. Apply the Cahn-Ingold-Prelog (CIP) priority rules.

Alkanes

• Cracking Alkanes: An Introduction: An introduction to the economic reasons and general process of cracking alkanes.
• Thermal vs. Catalytic Cracking: A detailed look at the differences between thermal and catalytic cracking, including conditions and products.
• Introduction to Alkanes and Fractional Distillation: Explore the definition of alkanes as saturated hydrocarbons and understand how fractional distillation separates crude oil.
• Free-Radical Chlorination of Methane: Explore the free-radical substitution mechanism in the chlorination of methane, including initiation, propagation, and termination steps.
• Fuels and Combustion: Explore alkanes as fuels, complete and incomplete combustion, and the formation of sulfur dioxide.
• Pollutants and Catalytic Converters: Learn about pollutants from internal combustion engines (NOx, CO, carbon, unburned hydrocarbons) and how catalytic converters remove them.
• Sulfur Dioxide Removal: Understand how calcium oxide or calcium carbonate are used to remove sulfur dioxide from flue gases.

Halogenoalkanes

• Elimination Reactions: Nucleophiles vs. Bases: Explore the dual role of reagents as both nucleophiles and bases in elimination reactions, focusing on the reaction mechanisms involved.
• Understanding Nucleophilic Substitution: Explore the polar nature of halogenoalkanes and their reactivity in nucleophilic substitution reactions.
• Mechanisms and Reaction Rates: Delve into the mechanisms of nucleophilic substitution reactions and investigate the influence of carbon-halogen bond enthalpy on reaction rates.
• Ozone Layer and CFCs: An introduction to the ozone layer, its importance, and the role of CFCs in its depletion.
• Mechanism of Ozone Depletion: Exploring the chemical equations behind ozone depletion and the catalytic role of chlorine atoms.
• CFCs and Legislation: Understanding the scientific evidence that led to the ban of CFCs and the development of alternative compounds.

Alkenes

• Electrophilic Addition Mechanisms: An introduction to electrophilic addition reactions of alkenes, focusing on reaction mechanisms and testing for unsaturation.
• Carbocation Stability and Product Formation: Explore the formation of major and minor products in alkene addition reactions, relating product distribution to carbocation stability.
• Addition Polymer Structure and Naming: Learn to draw repeating units from monomers and polymer chains, deduce monomer structure from polymers, and apply IUPAC naming rules.
• Properties, Uses, and Historical Context of Addition Polymers: Explore the unreactivity of addition polymers, intermolecular forces in polyalkenes, uses of PVC and the impact of plasticisers, and how our understanding of polymers has evolved.
• Alkenes: Structure and Bonding: Explore the structure, bonding, and electron density in alkenes.

Alcohols

• Biofuels and Fermentation: Explore the meaning of biofuels, the industrial production of ethanol via fermentation, and the carbon neutrality debate.
• Alkene Hydration and Environmental Impact: Understand alcohol production through alkene hydration, including the reaction mechanism and environmental and ethical considerations of biofuel use.
• Alcohol Elimination Reactions: Mechanisms and Alkene Formation: Explore the mechanism of water elimination from alcohols and how it leads to the formation of alkenes through acid-catalyzed reactions. Understand the process and its significance.
• Practical Skills: Elimination and Distillation: Covering the skills needed for Required practical 5. Learn how to perform the distillation of a product from a reaction following an elimination reaction.
• Alcohol Oxidation: Types and Equations: Learn about primary, secondary, and tertiary alcohols and how they are oxidised. This lesson covers the oxidation products, relevant equations using [O] as the oxidant and the role of acidified potassium dichromate(VI).
• Controlling Oxidation and Identifying Carbonyls: Understand how the oxidation method affects the product (aldehyde or carboxylic acid) for primary alcohols. Plus, learn how to distinguish between aldehydes and ketones using chemical tests like Fehling’s solution and Tollens’ reagent.

Organic analysis

• Understanding IR Spectroscopy: Explore the principles of infrared spectroscopy, including how bonds absorb radiation at specific wavenumbers and the use of the Chemistry Data Sheet to identify functional groups.
• Identifying Molecules and Global Warming: Learn about 'fingerprinting' in IR spectroscopy for molecule identification and investigate the connection between IR absorption by atmospheric gases and global warming.
• Using Mass Spectrometry to Determine Molecular Formula: Learn how precise atomic masses and molecular masses from mass spectrometry data can be used to determine the molecular formula of a compound.
• Functional Group Identification: Learn how to identify alcohols, aldehydes, alkenes, and carboxylic acids using test-tube reactions. Includes reactions of functional groups and required practical 6

Optical isomerism (A-level only)

• Introduction to Optical Isomerism: Explore the basics of optical isomerism, chirality, and enantiomers.
• Drawing and Understanding Enantiomers: Learn to draw structural and displayed formulas of enantiomers and understand their properties.
• Racemic Mixtures and Optical Inactivity: Understand how racemic mixtures are formed and why they are optically inactive.

Aldehydes and ketones (A-level only)

• Redox Reactions of Aldehydes and Ketones: Explore the reduction and oxidation reactions of aldehydes and ketones, focusing on reduction with NaBH4 and oxidation of aldehydes, including nucleophilic addition mechanisms.
• Hydroxynitriles from Carbonyls: Understand the formation of hydroxynitriles from aldehydes and ketones via nucleophilic addition with KCN, followed by dilute acid. Explore the stereochemical outcomes and associated hazards.
• Distinguishing Aldehydes and Ketones: Learn about chemical tests, such as Fehling's solution and Tollens' reagent, used to differentiate between aldehydes and ketones.

Carboxylic acids and derivatives (A-level only)

• Acyl Compounds: Structure and Properties: An introduction to acyl chlorides, acid anhydrides, and amides, their structures, and methods to test their purity.
• Acylation Reactions: Mechanisms and Applications: Explore the nucleophilic addition-elimination reactions of acyl chlorides and acid anhydrides with water, alcohols, ammonia, and primary amines, including reaction mechanisms and industrial applications.
• Practical: Preparing and Purifying an Ester: Guidance on Required Practical 10, focusing on the preparation of a pure organic liquid and test of its purity.
• Carboxylic Acids: Structure, Properties, and Formation: Explore the structure and properties of carboxylic acids, including their acidity and reactions with carbonates and alcohols to form esters.
• Esters: Formation, Uses, and Hydrolysis: Learn about the formation, common uses, and hydrolysis of esters under both acidic and alkaline conditions.
• Fats, Oils, Soaps and Biodiesel: Discover the structure and reactions of fats, oils and their alkaline hydrolysis to form soaps, alongside the production and importance of biodiesel.

Aromatic chemistry (A-level only)

• Benzene's Structure and Stability: Explore the unique bonding in benzene, its planar structure, bond lengths, and enhanced stability due to electron delocalisation.
• Benzene Reactions: Substitution vs. Addition: Understand why benzene favours substitution reactions over addition reactions.
• Nitration of Benzene: Explore the mechanism of nitration, including the generation of the nitronium ion and its role in synthesis.
• Friedel-Crafts Acylation: Understand Friedel-Crafts acylation, the role of the AlCl3 catalyst, and the importance of acylation reactions in synthesis.

Amines (A-level only)

• Amine Base Strength: Explore the base properties of amines, comparing their strength to ammonia and different types of amines.
• Amines as Nucleophiles: Substitution Reactions: Explore the nucleophilic nature of amines and ammonia, focusing on their substitution reactions with halogenoalkanes and the formation of different types of amines and quaternary ammonium salts.
• Addition-Elimination Reactions with Acyl Chlorides and Anhydrides: Examine the nucleophilic addition-elimination reactions of ammonia and primary amines with acyl chlorides and acid anhydrides, including reaction mechanisms.
• Quaternary Ammonium Salts as Cationic Surfactants: Learn about the properties and uses of quaternary ammonium salts, particularly their role as cationic surfactants.
• Preparation of Amines: Explore methods for preparing primary aliphatic and aromatic amines, including reactions with halogenoalkanes, reduction of nitriles, and reduction of nitro compounds.

Polymers (A-level only)

• Condensation Polymerisation: Monomers and Repeating Units: Explore the monomers used in condensation polymerisation (dicarboxylic acids, diols, diamines, and amino acids). Learn to draw repeating units from monomer structures and vice versa.
• Properties, Intermolecular Forces and Uses of Condensation Polymers: Examine the intermolecular forces in condensation polymers and relate these to their properties. Investigate typical uses of polyesters (eg Terylene) and polyamides (eg nylon 6,6 and Kevlar).
• Biodegradability of Polymers: Explore the chemical properties that determine polymer biodegradability, focusing on polyesters, polyamides, and polyalkenes.
• Polymer Disposal and Recycling: Analyse the advantages and disadvantages of different polymer disposal methods, including recycling.

Amino acids, proteins and DNA (A-level only)

• DNA Structure and Base Pairing: Explore the fundamental building blocks of DNA, including nucleotides, deoxyribose, phosphate ions, and the four bases. Understand how hydrogen bonding between complementary base pairs forms the double helix structure.
• DNA Polymerization: Learn how nucleotides polymerize to form a single strand of DNA through covalent bonds, creating a sugar-phosphate backbone with attached bases.
• Amino Acids and Zwitterions: Explore the dual nature of amino acids, focusing on zwitterion formation and their behaviour in acidic and alkaline solutions.
• Enzymes: Stereospecificity and Catalysis: Explore the catalytic action of enzymes, focusing on their stereospecific active sites and how they bind to substrate molecules.
• Enzyme Inhibition and Drug Design: Understand how drugs can act as enzyme inhibitors by blocking active sites and how computers aid in drug design.
• Cisplatin: How it Works: Explore the mechanism of cisplatin as an anticancer drug, focusing on its interaction with DNA and the consequences for cancer cells.
• Cisplatin: Balancing Benefits and Risks: Examine the adverse effects associated with cisplatin and consider the ethical and societal implications of using such drugs, weighing the benefits against the risks.
• Peptide Structures and Hydrolysis: Learn about the formation of peptides, their hydrolysis back to amino acids, and how to draw these structures.

Organic synthesis (A-level only)

• Green Chemistry Principles in Organic Synthesis: Explore the importance of sustainable practices in organic synthesis, including solvent reduction, safer starting materials, atom economy, and minimizing steps.
• Multi-Step Organic Synthesis: Learn to design and plan multi-step synthesis routes (up to four steps) for creating organic compounds using reactions from the A-level chemistry specification.

Nuclear magnetic resonance spectroscopy (A-level only)

• Introduction to NMR and TMS Standard: An introduction to Nuclear Magnetic Resonance (NMR) spectroscopy, covering the basics of 13C and 1H NMR, the chemical shift scale, the importance of the molecular environment, suitable solvents, and the use of tetramethylsilane (TMS) as a standard.
• Interpreting NMR Spectra and Integration: Learn how to interpret 1H and 13C NMR spectra, use chemical shift data to suggest possible structures, and use integration data to determine the relative numbers of equivalent protons.
• Spin-Spin Splitting and Analytical Techniques: Learn to deduce spin-spin splitting patterns using the n+1 rule (doublet, triplet, quartet) in aliphatic compounds and appreciate the use of multiple analytical techniques for structure confirmation.

Chromatography (A-level only)

• Chromatography Types: TLC, CC & GC (Part 1/4): Explore the three main types of chromatography: thin-layer chromatography (TLC), column chromatography (CC), and gas chromatography (GC). Understand the principles behind each technique and their applications.
• Chromatography Types: TLC, CC & GC (Part 2/4): Explore the three main types of chromatography: thin-layer chromatography (TLC), column chromatography (CC), and gas chromatography (GC). Understand the principles behind each technique and their applications.
• Chromatography Types: TLC, CC & GC (Part 3/4): Explore the three main types of chromatography: thin-layer chromatography (TLC), column chromatography (CC), and gas chromatography (GC). Understand the principles behind each technique and their applications.
• Chromatography Types: TLC, CC & GC (Part 4/4): Explore the three main types of chromatography: thin-layer chromatography (TLC), column chromatography (CC), and gas chromatography (GC). Understand the principles behind each technique and their applications.
• Calculations in Chromatography: Rf and Retention Times (Part 1/4): Learn how to calculate Rf values from chromatograms and compare retention times and Rf values with standards to identify different substances.
• Calculations in Chromatography: Rf and Retention Times (Part 2/4): Learn how to calculate Rf values from chromatograms and compare retention times and Rf values with standards to identify different substances.
• Calculations in Chromatography: Rf and Retention Times (Part 3/4): Learn how to calculate Rf values from chromatograms and compare retention times and Rf values with standards to identify different substances.
• Calculations in Chromatography: Rf and Retention Times (Part 4/4): Learn how to calculate Rf values from chromatograms and compare retention times and Rf values with standards to identify different substances.

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