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Edexcel International A Level Chemistry

Alkanes from Crude Oil

Crude oil is a mixture of hydrocarbons. These pages separate the key ideas students need for Topic 4: how fractions are separated by boiling temperature, how long-chain hydrocarbons are cracked into more useful molecules, and how reforming changes molecular structure to improve fuel quality.

Exam Unit
Unit 1
WCH11/01 – IAS
Specification Points
4.12
1 point covered
Sub-topics
3 lessons
Revision notes available
Exam Board
Edexcel IAL
Pearson International

Revision Notes

3 revision notes, in the order the specification teaches them.

A fractionating tower with liquids drawn off at different heights
1

Fractional Distillation

Revise how crude oil is separated into fractions using differences in boiling temperature and the temperature gradient in a fractionating column.

Start revising
A long hydrocarbon chain snapping into shorter pieces
2

Cracking

Learn how larger alkanes are broken down into shorter-chain alkanes and alkenes to meet demand for more useful products.

Start revising
A straight chain becoming a ring
3

Reforming

Review how straight-chain hydrocarbons can be converted into branched, cyclic or aromatic products that are more useful as fuels.

Start revising

Summary Map

Download, print and revise the reactions of this topic at a glance.

Summary maps

Download, print and revise the reactions of this topic at a glance.

Illustration of a summary map: compounds joined by reaction arrows
Summary map · PDF

Alkanes Map

Edexcel International A Level Chemistry · Unit 1 · Topic 4

Every reaction on one A4 page: reagents, conditions and reaction type for each arrow, colour coded, with the key tests.

Download the map5 reactions · A4 portrait · print ready
Illustration of a summary map: compounds joined by reaction arrows
Summary map · PDF

Alkanes Summary Map

Edexcel International A Level Chemistry · Unit 1 · Topic 4B Alkanes

The whole section on one A4 page: crude oil, cracking, reforming, combustion, pollutants and alternative fuels, with the free radical mechanism in a table.

Download the map6 key ideas + the mechanism · A4 portrait · print ready

© 2026 Online Learning System. For personal study: printing is allowed; editing, copying and redistribution are not.

Virtual Lessons

Recorded video lessons that teach the topic step by step.

Illustration of a video lesson playing on a screenWith the course

Virtual Lessons

Taught step by step in 4 recorded video lessons, to watch at your own pace.

Topic 4B Alkanes taught by a specialist chemistry teacher, in 4 recorded video lessons that follow the specification.

  • Learn it before you revise itEach lesson explains the chemistry step by step, with the diagrams, mechanisms and worked examples the exam expects.
  • At your own pacePause, rewind and rewatch any part. Each lesson opens where you stopped.
  • Your progress is keptA lesson is ticked off once you have watched most of it, here and in your course on Moodle.

MCQ Bank

Multiple-choice papers on this topic, marked the moment you submit. MCQ (A) is free.

Illustration of a multiple-choice paper with one answer tickedMCQ (A) free

Test yourself: 5 MCQ papers

Exam-style multiple-choice papers, marked the moment you submit with every answer explained. MCQ (A) is free.

5 exam-style multiple-choice papers, MCQ (A) to (E): 110 questions on Topic 4B Alkanes, written the way the exam asks them.

  • Marked the moment you submitYour score straight away, with every answer explained, right or wrong.
  • Revise what you missedEach explanation links to the revision notes for that point.
  • MCQ (A) is freeTry the first paper now. MCQ (B) to (E) come with the course.
Get the full course · £16.70
Open this topic in the MCQ Bank

SAQ Bank

Written, drawn and worked exam practice on this topic, marked by a specialist chemistry teacher.

Illustration of a written exam paper with a drawn structure and a penWith the course

Written and drawn answers: 10 papers

Draw, write and calculate the way the exam asks, then a specialist chemistry teacher marks your work.

10 exam papers, (A) to (J): 135 questions on Topic 4B Alkanes with no multiple choice. You write explanations, work out calculations and draw answers: structures, mechanisms and diagrams.

  • Answer the way the exam asksThe real paper wants written, worked and drawn answers, so that is how you practise.
  • Marked by a teacher, assisted by KASPA specialist chemistry teacher marks every answer against the mark scheme, with feedback on what to fix.
  • One paper marked each weekYour marked paper comes back here with every marking point shown.
Get the full course · £16.70
Open this topic in the SAQ Bank

Revision Game

Match reagents to products, free, with your board's reagents and conditions.

Illustration of memory game cards, two turned face up as a matching pairFree

Revision Game: Alkanes

Turn the cards over two at a time: match reagents to what they make, and find how each product is made.

A free memory game on the reactions in this topic, with your board's reagents, conditions and spec points.

  • Two ways to playMatch each set of reagents to what the reaction makes, or see a product and find the reactant and reagents that make it.
  • Drawn the way the exam draws themEvery structure is drawn in ChemDraw, with the reagents and conditions your exam board asks for.
  • It countsRounds earn XP and keep your streak going, and every correct match shows in your KASP analytics, apart from your marks.

Study Cards

Pick a deck, then turn each card to check what you remember.

Specification

Every specification point in this topic, in the exam board's own words. Rate how confident you are with each one.

Self-assessment · 40 points

Sign in to rate how confident you feel about each point. Your ratings are saved to your account, follow you to any device, and appear beside your KASP analytics, kept apart from your marks.

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4.9

  1. a

    know the general formula of alkanes

    Revise
  2. b

    know the general formula of cycloalkanes

  3. c

    understand that alkanes are hydrocarbons

    Revise
  4. d

    understand that cycloalkanes are hydrocarbons

  5. e

    understand that alkanes are saturated

    Revise
  6. f

    understand that cycloalkanes are saturated

    Revise

4.10

  1. a

    understand the term 'structural isomerism'

    Revise
  2. b

    be able to draw structural isomers of organic molecules given their molecular formula

    Revise

4.11

  1. a

    be able to draw structural isomers of alkanes with up to six carbon atoms

    Revise
  2. b

    be able to name structural isomers of alkanes with up to six carbon atoms

    Revise
  3. c

    be able to draw structural isomers of cycloalkanes with up to six carbon atoms

  4. d

    be able to name structural isomers of cycloalkanes with up to six carbon atoms

4.12

  1. a

    know that alkanes are used as fuels

    Revise
  2. b

    know that alkanes are obtained from fractional distillation of crude oil

    Revise
  3. c

    know that alkanes are obtained from cracking of crude oil fractions

    Revise
  4. d

    know that alkanes are obtained from reforming of crude oil fractions

    Revise
  5. e

    be able to write equations for fractional distillation/cracking/reforming reactions where relevant

    Revise

4.13

  1. a

    know that carbon monoxide is emitted during combustion of alkane fuels

    Revise
  2. b

    know that oxides of nitrogen is emitted during combustion of alkane fuels

    Revise
  3. c

    know that oxides of sulfur is emitted during combustion of alkane fuels

    Revise
  4. d

    know that carbon particulates is emitted during combustion of alkane fuels

    Revise
  5. e

    know that unburned hydrocarbons is emitted during combustion of alkane fuels

    Revise

4.14

  1. a

    understand the toxicity problem arising from carbon monoxide produced during combustion of alkane fuels

    Revise
  2. b

    understand why carbon monoxide is toxic

    Revise
  3. c

    understand the acidity problem arising from oxides of nitrogen produced during combustion of alkane fuels

    Revise
  4. d

    understand the acidity problem arising from oxides of sulfur produced during combustion of alkane fuels

    Revise

4.15

  1. a

    be able to discuss reasons for developing alternative fuels in terms of sustainability

    Revise
  2. b

    be able to discuss reasons for developing alternative fuels in terms of reducing emissions

    Revise
  3. c

    be able to discuss reasons for developing alternative fuels in terms of CO2 emissions and climate change

    Revise

4.16

  1. a

    be able to apply the concept of carbon neutrality to petrol

    Revise
  2. b

    be able to apply the concept of carbon neutrality to bioethanol

    Revise
  3. c

    be able to apply the concept of carbon neutrality to hydrogen

4.17

  1. i

    understand the reactions of alkanes with: oxygen in the air (combustion)

    Revise
  2. ii

    understand the reactions of alkanes with: halogens

    Revise

4.18

  1. i

    understand the mechanism of the free radical substitution reaction between an alkane and a halogen: using free radicals, which are species with an unpaired electron, represented by a single dot

    Revise
  2. ii

    understand the mechanism of the free radical substitution reaction between an alkane and a halogen: showing the initiation step of the mechanism, with curly half-arrows for free radical formation

    Revise
  3. iii

    understand the mechanism of the free radical substitution reaction between an alkane and a halogen: showing the propagation and termination steps of the mechanism

    Revise
  4. iii a

    understand the propagation steps of the free radical substitution reaction between an alkane and a halogen

    Revise
  5. iii b

    understand the termination steps of the free radical substitution reaction between an alkane and a halogen

    Revise
  6. iv

    understand the mechanism of the free radical substitution reaction between an alkane and a halogen: having limited use in synthesis because of further substitution reactions

    Revise