Chemistry study notes
Organic Chemistry
Recognise molecular families and connect structures, reactions, fuels and materials.
O-Level 6092 (2026) / SEC G3 K324 (2027)
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9 topicsFuels, fractions and bioethanol
Follow carbon from a resource to useful products.
Alkanes: build a valid carbon skeleton
Use four bonds per carbon and one per hydrogen.
Alkenes: a double bond creates new reactions
Distinguish substitution, addition and cracking.
Alcohols: identify -OH and follow ethanol
Structure connects preparation, combustion and oxidation.
Carboxylic acids: recognise -COOH
A functional group gives a family its characteristic chemistry.
Esters: join two fragments and keep track of their origins
The name has an alcohol part followed by an acid part.
Pure onlyAddition polymers: open the double bond, keep the substituents
A repeat unit shows the pattern within a long chain.
Condensation polymers and depolymerisation
Recognise the linkage that is made or broken.
Pure onlyEvaluate plastic use and recycling
Compare what happens to the molecules and to the wider system.
Scope
Learning outcomes
11. Organic Chemistry (6092 / K324). Use the outcome map to find the explanation for a particular syllabus requirement.
See the learning outcome map
11.1(a) Identify non-renewable fuel sources
- Natural gas mainly methane
- Crude oil
11.1(b) Explain crude-oil fractionation
- Hydrocarbon mixture
- Fractions
- Competing fuel and chemical feedstock uses
11.1(c) Recognise renewable biofuel
- Bioethanol from sugarcane
11.1(d) Compare carbon impacts of fuels
- Plant-growth uptake offsets burning emissions
- Compare fossil-carbon release
- Sustainability depends on wider inputs
11.2(a) Describe homologous series
- General formula
- Similar chemistry
- Gradual melting/boiling/viscosity change with size/mass
Alkanes: build a valid carbon skeletonFuels, fractions and bioethanol
11.2(b) Describe alkanes
- Saturated hydrocarbons
- CnH2n+2
11.2(e) Describe alkane reactions
- Methane combustion
- Chlorine substitution with UV
- Generally unreactive otherwise
11.2(f) Describe alkenes
- Unsaturated hydrocarbons
- CnH2n
11.2(h) Explain cracking
- Alkenes and hydrogen products
- Demand for smaller refinery molecules
- Heating/catalyst conditions
Alkenes: a double bond creates new reactionsFuels, fractions and bioethanol
11.2(i) Distinguish saturation
- Molecular structure
- Aqueous bromine test
11.2(k) Explain polyunsaturated food molecules
- More than one C=C
11.2(l) Explain margarine manufacture
- Hydrogen addition to vegetable oils
- Solid product
- Nickel catalyst and heat
11.2(c) Draw and name alkanes
- Branched and unbranched C1-C4
- Names methane to butane
- Displayed-formula method
11.2(d) Identify isomerism
- Same molecular formula; different structural formulae
11.2(g) Draw and name alkenes
- Branched/unbranched C2-C4
- Ethene to butene
- Valency check
11.2(j) Describe ethene reactions
- Combustion
- Polymerisation
- Addition of bromine, steam and hydrogen
- Essential reagents/conditions
Alkenes: a double bond creates new reactionsAddition polymers: open the double bond, keep the substituents
11.3(a) Recognise alcohol series
- -OH group
11.3(c) Describe alcohol reactions
- Combustion
- Oxidation to acids, exemplified by ethanol
11.3(e) Recognise carboxylic-acid series
- -CO2H/-COOH group
11.3(b) Draw and name alcohols
- Branched/unbranched C1-C4
- Methanol to butanol
- OH position
11.3(d) Describe ethanol production
- Catalysed steam addition to ethene
- Glucose fermentation
- Essential conditions
Alcohols: identify -OH and follow ethanolAlkenes: a double bond creates new reactions
11.3(f) Draw and name carboxylic acids
- C1-C4 structures
- Methanoic to butanoic acid
11.3(g) Explain acid reactions
- Weak ionisation
- Carbonates, bases and suitable metals
11.3(h) Explain ethanol oxidation
- Atmospheric oxygen
- Acidified KMnO4
Alcohols: identify -OH and follow ethanolCarboxylic acids: recognise -COOH
11.3(i) Explain ester formation
- Acid plus alcohol
- Ethyl ethanoate example
- Catalyst and warming
11.3(j) Deduce ester names/formulae and precursors
- Unbranched C1-C4 acids and alcohols
- Forward and reverse deduction
11.4(a) Describe polymers and monomers
- Large molecules from small units
- Different monomers give different polymers
- Different linkages
Addition polymers: open the double bond, keep the substituentsCondensation polymers and depolymerisation
11.4(b) Explain poly(ethene) formation
- Addition polymerisation of ethene
Addition polymers: open the double bond, keep the substituents
11.4(c) Identify poly(ethene) uses
- Plastic bags
- Clingfilm
Addition polymers: open the double bond, keep the substituents
11.4(d) Deduce addition-polymer structures
- Monomer to repeat unit
- Repeat unit to monomer
Addition polymers: open the double bond, keep the substituentsCondensation polymers and depolymerisation
11.4(g) Explain plastic pollution
- Non-biodegradability
- Disposal impacts
11.4(h) Compare recycling routes
- Physical: poly(ethene) melted into pellets
- Chemical: cracking into fuel
- Depolymerisation to feedstock
Evaluate plastic use and recyclingCondensation polymers and depolymerisation
11.4(j) Evaluate recycling issues
- Social
- Economic
- Environmental
11.4(e) Recognise condensation polymers
- Nylon polyamide partial structure
- Terylene polyester partial structure
- No manufacture mechanisms
11.4(f) Identify man-made fibre uses
- Clothing, curtains, fishing line, parachutes, sleeping bags
11.4(i) Explain depolymerisation
- Polymers to monomers
- Acid-catalysed polyester hydrolysis
- No mechanism