Chemistry study notes
Organic Chemistry
Recognise molecular families and connect structures, reactions, fuels and materials.
O-Level 5086 / 5088 (2026) / SEC G3 K326 / K328 (2027)
Choose a topic
7 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.
Addition polymers: open the double bond, keep the substituents
A repeat unit shows the pattern within a long chain.
Evaluate plastic use and recycling
Compare what happens to the molecules and to the wider system.
Scope and references
Learning outcomes and sources
11. Organic Chemistry (5086 / 5088 / K326 / K328). 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(d) Describe alkane reactions
- Methane combustion
- Chlorine substitution with UV
- Generally unreactive otherwise
11.2(e) Describe alkenes
- Unsaturated hydrocarbons
- CnH2n
11.2(g) 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(h) Distinguish saturation
- Molecular structure
- Aqueous bromine test
11.2(j) Explain polyunsaturated food molecules
- More than one C=C
11.2(k) Explain margarine manufacture
- Hydrogen addition to vegetable oils
- Solid product
- Nickel catalyst and heat
11.2(c) Draw and name alkanes
- Unbranched C1-C3
- Methane to propane
11.2(f) Draw and name alkenes
- Unbranched C2-C3
- Ethene and propene
11.2(i) Describe ethene reactions
- Combustion
- Polymerisation
- Bromine and hydrogen addition
- Essential 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
- Unbranched C1-C3
- Methanol to propanol
11.3(d) Describe ethanol fermentation
- Glucose
- Yeast, warmth and oxygen exclusion
11.3(f) Explain ethanol oxidation
- Atmospheric oxygen
- Acidified KMnO4
Alcohols: identify -OH and follow ethanolCarboxylic acids: recognise -COOH
11.4(a) Describe polymers and monomers
- Large molecules from small units
- Different monomers give different polymers
Addition polymers: open the double bond, keep the substituents
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 substituents
11.4(e) Explain plastic pollution
- Non-biodegradability
- Disposal impacts
11.4(f) Compare recycling routes
- Physical: poly(ethene) melted into pellets
- Chemical: cracking into fuel
11.4(g) Evaluate recycling issues
- Social
- Economic
- Environmental
- 2026 Pure Chemistry 6092
Official topic 11, pages 21-23. Original explanations mapped to the stated outcomes; 2026 and 2027 topic content agrees.
- 2027 Pure Chemistry K324
Official topic 11, pages 21-23. Original explanations mapped to the stated outcomes; 2026 and 2027 topic content agrees.
- 2026 Combined Chemistry 5086 / 5088
Official topic 11, pages 34-36. Original explanations mapped to the stated outcomes; 2026 and 2027 topic content agrees.
- 2027 Combined Chemistry K326 / K328
Official topic 11, pages 34-36. Original explanations mapped to the stated outcomes; 2026 and 2027 topic content agrees.
- Grail: 6092 Chemistry Complete Notes, Version 1
Background consultation: Chapters 19-21, small organic structures and polymer links, pp. 77-89; official Pure p. 23 polymer diagrams inspected separately. Teaching additions and examples are original; syllabus scope and chemistry independently checked.