Topic 7: Organic chemistry – GCSE AQA Higher Chemistry revision notes

What this topic covers

Topic 7: Organic chemistry has 3 subtopics:

• Carbon compounds as fuels and feedstock
• Reactions of alkenes and alcohols (chemistry only)
• Synthetic and naturally occurring polymers (chemistry only)

Topic 7: Organic chemistry lessons by subtopic

23 lessons, grouped by subtopic.

Carbon compounds as fuels and feedstock

• Separating Crude Oil by Fractional Distillation: Learn how fractional distillation separates crude oil into useful fractions containing hydrocarbons with similar numbers of carbon atoms, and understand the process in terms of evaporation and condensation.
• From Crude Oil to Modern Life - Fuels and Petrochemicals: Explore how crude oil fractions are processed into essential fuels like petrol, diesel and kerosene, and discover the wide range of petrochemical products that support modern life including polymers, solvents and detergents.
• What is crude oil and where does it come from?: Learn about crude oil as a finite resource, its formation from ancient biomass, and understand that it is a mixture of many compounds, mostly hydrocarbons.
• Understanding alkanes - the main hydrocarbons in crude oil: Discover that most hydrocarbons in crude oil are alkanes, learn their general formula CnH2n+2, and identify the first four alkanes: methane, ethane, propane and butane.
• Representing and recognising alkane molecules: Learn the different ways to represent alkane molecules using molecular and structural formulae, and practice recognising alkanes from their formulae.
• Introduction to Cracking and Its Methods: Students learn what cracking is, why it's needed, and explore the two main methods of cracking hydrocarbons. They will understand the general conditions used for catalytic and steam cracking, and discover how cracking produces smaller, more useful molecules including alkanes and alkenes.
• Alkenes: Properties and Testing: Students investigate alkenes as products of cracking, learning about their increased reactivity compared to alkanes. They will study the bromine water test for alkenes, including the colour change observed, and practice balancing cracking equations using given formulae.
• Uses and Importance of Cracking Products: Students explore the practical applications of cracking products, including alkenes as starting materials for polymers and other chemicals. They will examine real-world examples of cracking's usefulness and analyze how modern life depends on hydrocarbon uses.

Reactions of alkenes and alcohols (chemistry only)

• Introduction to Alcohols and Their Structure: Learn about the alcohol functional group, identify the first four alcohols (methanol, ethanol, propanol, butanol) as a homologous series, and understand different ways to represent alcohol structures including molecular and displayed formulae.
• Reactions and Properties of Alcohols: Explore what happens when the first four alcohols react with sodium, burn in air, dissolve in water, and react with oxidising agents. Learn the main uses of these important alcohols in everyday life.
• Fermentation and Alcohol Production: Understand how ethanol is produced through fermentation of sugar solutions using yeast, including the specific conditions required for this important biological process.
• Introduction to Alkenes and Their General Formula: Learn what alkenes are, their general formula CnH2n, and understand why they are classified as unsaturated hydrocarbons compared to alkanes.
• Naming and Representing Alkenes: Identify the first four members of the alkene homologous series (ethene, propene, butene, pentene) and learn the different ways to represent alkene molecules using molecular and structural formulae.
• Introduction to Carboxylic Acids: Learn about the functional group and structure of carboxylic acids, including the first four members of the homologous series and how to recognise them from names and formulae.
• Chemical Properties of Carboxylic Acids: Explore the reactions of carboxylic acids with carbonates, water, and alcohols, and understand why they are weak acids in terms of ionisation and pH.
• Introduction to Alkenes and Their Structure: Learn about alkenes as hydrocarbons with the C=C functional group, understand how functional groups determine organic reactions, and explore the combustion properties of alkenes including why they burn with smoky flames.

Synthetic and naturally occurring polymers (chemistry only)

• What are Addition Polymers?: Understanding the basic concept of addition polymerisation, identifying monomers and polymers from diagrams, and recognising the C=C functional group in alkene monomers.
• Drawing Addition Polymerisation Reactions: Learning to draw diagrams showing polymer formation from alkene monomers, understanding repeating units, and exploring examples like poly(ethene) formation.
• Understanding Condensation Polymerisation: Learn how condensation polymerisation works, involving monomers with two functional groups that join together by losing small molecules like water, and explore the simplest polymers formed from two different monomers.
• Formation of Polyesters from Ethanediol and Hexanedioic Acid: Examine the specific example of how ethanediol and hexanedioic acid monomers polymerise to produce a polyester through condensation polymerisation.
• Amino Acids and Polypeptide Formation: Students will learn about the structure of amino acids with their two functional groups, understand how amino acids undergo condensation polymerisation to form polypeptides using glycine as an example, and explore how different amino acids can combine in chains to produce proteins.
• DNA Structure and Function: Explore DNA as a large molecule essential for life, understanding its role in encoding genetic instructions and its double helix structure made from nucleotide monomers.
• Naturally Occurring Polymers and Their Monomers: Identify the different types of naturally occurring polymers important for life including proteins, starch and cellulose, and learn to name the monomers from which these polymers are made.

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