What does the CCEA A2 2 Organic Chemistry unit cover?

It is the externally assessed A2 chemistry unit of Life and Health Sciences. It covers the classification of organic compounds by functional group, homologous series and IUPAC nomenclature, the characteristic reactions of alkanes, alkenes, alcohols and carboxylic acids, structural and stereoisomerism (including cis-trans isomerism), instrumental analysis (mass spectrometry, infrared spectroscopy and chromatography), and addition and condensation polymers with their uses and environmental impact.

What is the test that distinguishes an alkene from an alkane?

Add bromine water, which is orange or yellow-brown. An alkene decolourises bromine water rapidly because the bromine adds across the carbon-to-carbon double bond in an addition reaction, turning it colourless. An alkane has no double bond and does not react under these conditions, so the colour stays. The decolourising of bromine water therefore identifies an alkene.

What happens when a primary alcohol is oxidised?

A primary alcohol is oxidised first to an aldehyde and then, with excess oxidising agent under reflux, to a carboxylic acid. Acidified potassium dichromate is the usual oxidising agent, and it changes colour from orange to green as it is reduced. Distilling the product off as it forms stops the oxidation at the aldehyde stage, while heating under reflux drives it on to the acid.

What is the difference between addition and condensation polymerisation?

Addition polymerisation joins many unsaturated alkene monomers as their double bonds open, forming one long saturated chain with no other product, for example poly(ethene). Condensation polymerisation joins monomers each with two reactive functional groups, losing a small molecule (usually water) each time a bond forms, giving ester or amide linkages, as in polyesters and proteins. Addition polymers are generally not biodegradable.

How should I revise the Organic Chemistry unit?

Start with functional groups and IUPAC naming, because everything else builds on them. Learn the characteristic reactions of each family and the reaction types (combustion, substitution, addition, oxidation), and the key tests (bromine water for alkenes, the orange-to-green dichromate change for alcohol oxidation). Practise drawing isomers and recognising cis-trans isomerism, learn to interpret mass, infrared and chromatography data, and contrast addition with condensation polymerisation.

Northern IrelandLife & Health Sciences

CCEA Life and Health Sciences A2 2 Organic Chemistry: a complete overview of functional groups, reactions, isomerism, instrumental analysis and polymers

A deep-dive CCEA Life and Health Sciences guide to the externally assessed A2 2 Organic Chemistry unit. Covers functional groups and nomenclature, the reactions of the main organic families, structural and stereoisomerism, instrumental analysis, and addition and condensation polymers, with the skills CCEA examines.

Generated by Claude Opus 4.818 min readCCEAUpdated 2026-06-16

Reviewed by: AI editorial process; not yet individually human-reviewed

Jump to a section

What this unit demands
Functional groups and reactions
Isomerism
Instrumental analysis and polymers
How this unit is examined
Check your knowledge

What this unit demands

Organic Chemistry (A2 2) is the externally assessed A2 chemistry core of CCEA Life and Health Sciences. It tests the systematic chemistry of carbon compounds: how they are named and classified, how each family reacts, how isomers differ, how modern instruments identify them, and how polymers are made and disposed of. The examiners reward correct IUPAC naming, predicting products and reaction types, drawing isomers, interpreting spectra and chromatograms, and contrasting the two kinds of polymerisation.

This guide pulls the five dot points of the unit together, then sets out the exam patterns CCEA repeats. Each topic has a matching dot-point page with practice questions; this overview ties them into one picture.

Functional groups and reactions

Organic compounds are classified by functional group into homologous series with shared general formulae and similar chemistry. IUPAC names are built from a stem (carbon count), a suffix (bonding and functional group) and locant numbers. The families react characteristically: alkanes by combustion and substitution; alkenes by addition (decolourising bromine water); alcohols by combustion, oxidation (to aldehydes then carboxylic acids, with the orange-to-green dichromate change) and dehydration; and carboxylic acids as weak acids. The reaction types to recognise are combustion, substitution, addition and oxidation.

Isomerism

Isomers share a molecular formula but differ in arrangement. Structural isomers differ in structure (chain, position or functional group isomers). Stereoisomers differ in spatial arrangement; cis-trans (E-Z) isomerism occurs in alkenes because of restricted rotation about the double bond, but only when each double-bond carbon carries two different groups. Isomers can differ in boiling point, reactivity and biological activity, which matters greatly in pharmacology.

Instrumental analysis and polymers

Mass spectrometry gives the relative molecular mass (molecular ion peak) and structural clues (fragment peaks); infrared spectroscopy identifies functional groups from characteristic absorption frequencies; and chromatography separates mixtures, with the Rf value identifying components. Polymers form by addition (unsaturated monomers, no small molecule lost, durable and non-biodegradable, like poly(ethene)) or condensation (monomers with two functional groups, losing water, with ester or amide linkages, like polyesters and proteins). Disposal by landfill, incineration and recycling each has drawbacks.

How this unit is examined

A typical CCEA profile for Organic Chemistry:

Naming and structure. IUPAC names, formulae and converting between representations.
Reactions. Predicting products, naming reaction types, and the key tests.
Isomerism. Drawing structural isomers and explaining cis-trans isomerism.
Analysis. Interpreting mass spectra, infrared spectra and chromatograms (including Rf).
Polymers. Addition versus condensation, and environmental impact and disposal.

Check your knowledge

A mix of naming, reaction and analysis questions covering the unit. Attempt them under timed conditions, then check against the solutions.

Define a homologous series. (2 marks)
Give the IUPAC name of CH3CH2CH2OH. (1 mark)
Name the reaction type and product when ethene reacts with bromine. (2 marks)
State the products of complete oxidation of a primary alcohol and the colour change. (2 marks)
State the two conditions for cis-trans isomerism. (2 marks)
State what the molecular ion peak in a mass spectrum gives. (1 mark)
Calculate the Rf value if a spot moves 3.0 cm and the solvent front moves 12.0 cm. (2 marks)
State the key difference between addition and condensation polymerisation. (2 marks)

Sources & how we know this

CCEA GCE Life and Health Sciences specification — CCEA (2016)