Key term
CCEA AS-Level Chemistry 1110
Formulae, Equations and Amounts of Substance
Atomic Structure
Topic overviewProtons, neutrons and electronsAtomic number, mass number and the composition of ionsIsotopes and relative isotopic massRelative atomic, molecular and formula massMass spectra and relative atomic mass calculationsMass spectra of diatomic elementsElectronic configuration and the building up principleOrbitals, electron spin and orbital shapesThe s-, p-, d- and f-blocks of the Periodic TableIonisation energies and their equationsTrends in ionisation energy as evidence for shells and subshells
Bonding
Topic overviewIonic bonding and electron transferDot and cross diagrams for ionic compoundsCovalent bonding and the shared pairLone pairs and co-ordinate bondingDot and cross diagrams for covalent molecules and ionsThe octet rule and its limitationsElectronegativity and bond polarityMetallic bonding
Intermolecular Forces and Structure
Shapes of Molecules and Ions
Redox
The Halogens
Acid-Base Titrations
Qualitative Tests
Formulae and Amounts of a Substance
Nomenclature and Isomerism in Organic Chemistry
Alkanes
Topic overviewAlkanes as saturated hydrocarbonsBoiling points of alkanes and van der Waals' forcesBoiling points of branched isomersComplete and incomplete combustion of alkanesPollutants from alkane fuels and the atmosphereCatalytic convertersRadicals, homolytic fission and heterolytic fissionFree radical substitution of alkanes
Alkenes
Topic overviewUnsaturated hydrocarbons and the bromine water testSigma and pi bonds in the carbon–carbon double bondElectron density at C=C, reactivity and catalytic hydrogenationAddition of chlorine and bromine to alkenesAddition of hydrogen chloride and hydrogen bromideElectrophiles, heterolytic fission and the addition mechanismCarbocation stability and Markovnikov additionAddition polymerisation of alkenes
Halogenoalkanes
Topic overviewClassification and boiling points of halogenoalkanesLaboratory preparation of a halogenoalkane from an alcoholNucleophiles and hydrolysis with aqueous alkaliReactions with ammonia and with potassium cyanideRelative rates of hydrolysis and carbon–halogen bond enthalpyElimination using ethanolic potassium hydroxideCFCs and the ozone layer
Alcohols
Infrared Spectroscopy
Energetics
Topic overviewExothermic and endothermic changesStandard conditions and the standard enthalpy changeEnthalpy level diagramsStandard enthalpies of combustion and formationStandard enthalpy of neutralisationMeasuring enthalpy changes by experimentEnthalpy calculations using q = mcΔTHess's Law and enthalpy cyclesIndirect enthalpy calculations using Hess's LawAverage bond enthalpies and their limitations
Kinetics
Equilibrium
Group II Elements and Their Compounds
Topic overviews-block character and electronic configurationTrends in atomic radius and first ionisation energyReactions of the elements with oxygen, water and dilute acidsThe oxides and their reactions with water and dilute acidsThermal stability of the carbonates and hydroxidesUses of magnesium oxide, calcium carbonate and limeSolubility trends and solubility curves
Alkanes
- 8 subtopics
- 24 things to know
- Unit AS 2
What Alkanes covers
Alkanes is examined in Unit AS 2, Further Physical and Inorganic Chemistry and an Introduction to Organic Chemistry, and drawn on again in Unit AS 3, Basic Practical Chemistry. It covers alkanes as saturated hydrocarbons, boiling points of alkanes and van der Waals' forces, boiling points of branched isomers, complete and incomplete combustion of alkanes, pollutants from alkane fuels and the atmosphere, catalytic converters, radicals, homolytic fission and heterolytic fission and free radical substitution of alkanes.
Where it is assessed
Unit AS 2
Further Physical and Inorganic Chemistry and an Introduction to Organic Chemistry, and again in Unit AS 3, Basic Practical Chemistry.
Check the CCEA specification ↗The 8 subtopics
Each one has its own page. CCEA AS Chemistry students sit this topic in the first year.
- Alkanes as saturated hydrocarbonsTerm hydrocarbon, general formula of the alkanes and bond joins the carbon atoms in an alkane.Open →
- Boiling points of alkanes and van der Waals' forcesRecall questions on what van der Waals' forces are and how a temporary dipole induces attraction, why they act between all molecules, why boiling point rises with chain length, which bonds break on boiling, the trend in volatility, and why an alkane boils far below an alcohol of similar mass.Open →
- Boiling points of branched isomersRecall questions on the effect of branching on boiling point and the reason in terms of contact between molecules, ordering the isomers of pentane and of hexane, why isomers with the same number of electrons still differ, and using a boiling point to tell one isomer from another.Open →
- Complete and incomplete combustion of alkanesAppearance of the flame when an alkane burns completely and appearance of the flame when an alkane burns incompletely.Open →
- Pollutants from alkane fuels and the atmosphereRecall questions on the five pollutants from burning alkane fuels, how carbon monoxide and the oxides of nitrogen form in an engine and what harm each does, where the sulfur comes from, particulates and unburned hydrocarbons, the rise in atmospheric carbon dioxide, and both sides of the case for hydrocarbon fuels.Open →
- Catalytic convertersPurpose of a catalytic converter in a car exhaust, catalysis takes place in a catalytic converter and catalyst poisoning.Open →
- Radicals, homolytic fission and heterolytic fissionTerm radical, term homolytic fission and term heterolytic fission.Open →
- Free radical substitution of alkanesMechanism operates when methane reacts with chlorine and three stages of the free radical substitution mechanism.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
Why does an alkane boil at a much lower temperature than an alcohol of similar relative molecular mass?
Evaluation
Give one argument in favour of continuing to burn hydrocarbon fuels and one argument against.
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Outline how a heterogeneous catalyst brings about a reaction between two gases.
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What is meant by the term hydrocarbon?
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Explain, in terms of van der Waals' forces, why a branched alkane boils at a lower temperature than its unbranched isomer.
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Which two products are always formed when an alkane burns completely?
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Define the term radical.
Process
What type of mechanism operates when methane reacts with chlorine?
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Why are alkanes described as saturated hydrocarbons?
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Which of pentane and 2,2-dimethylpropane has the higher boiling point?
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What condition is needed for the complete combustion of an alkane?
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Name five pollutants produced during the combustion of alkane fuels.
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What is the purpose of a catalytic converter in a car exhaust?
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How is a radical represented in a chemical equation?
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What conditions are required for the halogenation of an alkane?
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State the general formula of the alkanes.
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Why do van der Waals' forces act between all molecules?
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Two isomers contain exactly the same number of electrons, so why do they boil at different temperatures?
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Write the equation for the complete combustion of methane.
Process
How is carbon monoxide formed when a fuel burns in an engine?
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Which metals are used as the catalyst in a catalytic converter?
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Write the equation for the homolytic fission of a chlorine molecule.
Key term
Write the overall equation for the reaction of methane with chlorine to give chloromethane.
Take Alkanes further
The same content, four other ways.
Questions from this topic
Each one with the model answer underneath.
- 1
What is meant by the term hydrocarbon?
Model answer
A hydrocarbon is a compound containing the elements carbon and hydrogen only.
- 2
Why are alkanes described as saturated hydrocarbons?
Model answer
Every bond between the carbon atoms is a single bond, so each molecule already holds the largest possible number of hydrogen atoms and cannot take up any more.
- 3
State the general formula of the alkanes.
Model answer
The alkanes have the general formula CₙH₂ₙ₊₂.
- 4
Give the molecular formula of the unbranched alkane containing eight carbon atoms.
Model answer
Putting n = 8 into CₙH₂ₙ₊₂ gives the molecular formula C₈H₁₈.
- 5
What type of bond joins the carbon atoms in an alkane?
Model answer
The carbon atoms are joined by single covalent sigma bonds formed by the head-on overlap of orbitals.
- 6
State the bond angle around each carbon atom in an alkane and explain it.
Model answer
The bond angle is 109.5°, because each carbon atom has four bonding pairs of electrons that repel one another equally into a tetrahedral arrangement.
What is inside Levo
Six ways to work the same material.
Alkanes revision questions
- Is Alkanes examined at AS in CCEA Chemistry?
- Yes. It sits in Unit AS 2, which you take in the first year, so it is on the AS paper as well as counting towards the full A level.
- What does Alkanes cover in CCEA AS-Level Chemistry?
- 8 subtopics: alkanes as saturated hydrocarbons, boiling points of alkanes and van der waals' forces, boiling points of branched isomers, complete and incomplete combustion of alkanes, pollutants from alkane fuels and the atmosphere, catalytic converters, radicals, homolytic fission and heterolytic fission and free radical substitution of alkanes. Each one has its own page with questions and model answers.
- How is Alkanes organised?
- By the CCEA 1110 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Alkanes, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
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