Evaluation
Eduqas A-Level Chemistry A410QS
Formulae and Equations
Basic Ideas About Atoms
Topic overviewRadioactive decay and nuclear equationsBehaviour of α, β and γ radiationHalf-life and radioactive decay calculationsRadiation hazards and the uses of radioisotopesIonisation energy and its variation between elementsSuccessive ionisation energies and electronic structureOrbitals and electron configurations of elements 1 to 36Emission and absorption spectraThe hydrogen spectrum, E = hf and the convergence limit
Chemical Calculations
Topic overviewRelative atomic, isotopic, formula and molecular massPrinciples of the mass spectrometerMass spectra, isotopic abundance and relative atomic massEmpirical and molecular formulaeThe mole, the Avogadro constant and molar massMoles, grams and numbers of particlesConcentration and solubilityMolar volume and gas volume correctionsThe ideal gas equationStoichiometry and reacting quantitiesAcid-base titration calculationsAtom economy, percentage yield and percentage error
Bonding
Solid Structures
The Periodic Table
Topic overviewArrangement of the elements and the s-, p- and d-blocksOxidation and reduction as electron transferTrends across periods and down groupsReactions of Group 2 elements with oxygen, water and steamReactions of the aqueous cations Mg²⁺, Ca²⁺ and Ba²⁺Flame coloursReactivity of Group 1 and Group 2 metalsThermal stability of the Group 2 carbonates and hydroxidesSolubility of the Group 2 hydroxides and sulfatesBasic character of the Group 1 and Group 2 oxides and hydroxidesVolatility of the halogens and their reactions with metalsOxidising power, displacement reactions and the silver nitrate testWater treatment, salt preparation and gravimetric analysis
Simple Equilibria and Acid-Base Reactions
Thermochemistry
Rates of Reaction
The Wider Impact of Chemistry
Organic Compounds
Hydrocarbons
Topic overviewAlkanes and the sigma-bonded frameworkCombustion of alkanes and the use of fossil fuelsFree radical substitution and the photochlorination of alkanesAlkenes and the reactivity of the C=C bondE–Z isomerismElectrophilic addition of bromine to alkenesTests for alkenesMarkovnikov addition of hydrogen bromide and carbocation stabilityCatalytic hydrogenation of alkenesAddition polymerisation
Halogenoalkanes
Topic overviewNucleophilic substitution of primary halogenoalkanesElimination reactions forming alkenesBond polarity, bond enthalpy and the ease of substitutionThe silver nitrate test for halogenoalkanesUses of halogenoalkanes and the regulation of their useCFCs and their effect in the upper atmosphereHeating under reflux
Alcohols and Carboxylic Acids
Topic overviewIndustrial preparation of ethanol from etheneFermentation and the distillation of ethanolBiofuels and the issues they raiseClassifying alcohols as primary, secondary and tertiaryDehydration of alcohols to alkenesOxidation of primary alcohols to aldehydes and carboxylic acidsOxidation of secondary alcohols to ketonesThe dichromate(VI) test for alcoholsCarboxylic acids and the sodium hydrogencarbonate testReactions of carboxylic acids with bases, carbonates and hydrogencarbonatesEsterification and separation by distillation
Instrumental Analysis
Redox and Standard Electrode Potential
Redox Reactions
Chemistry of the P-Block
Topic overviewAmphoteric behaviour of aluminium and leadThe inert pair effect in Groups 3, 4 and 5Electron-deficient compounds and expanded octetsAl₂Cl₆ and donor-acceptor compoundsHexagonal and cubic boron nitrideStability of oxidation states II and IV in Group 4Carbon dioxide and lead(II) oxideBonding in the Group 4 chloridesHydrolysis of the Group 4 chloridesReactions of aqueous lead(II) ionsChlorine with cold and warm aqueous sodium hydroxideBleaching and bactericidal action of chlorine and chlorate(I)Sodium halides with concentrated sulfuric acid
Chemistry of the D-Block Transition Metals
Topic overviewOxidation states of the d-block elementsImportant oxidation states and the colours of aqueous ionsBonding in tetrahedral and octahedral complexesThe origin of colour and the splitting of d-orbitalsLigand exchange and change of coordination numberColours and formulae of copper and cobalt complex ionsHeterogeneous and homogeneous catalysisNickel in hydrogenation and iron in the Haber processVanadium(V) oxide and manganese(IV) oxide as catalystsReactions of Cr³⁺, Fe²⁺, Fe³⁺ and Cu²⁺ with excess aqueous hydroxide
Chemical Kinetics
Enthalpy Changes for Solids and Solutions
Entropy and Feasibility of Reactions
Equilibrium Constants
Acid-Base Equilibria
Topic overviewThe Lowry–Brønsted theory and conjugate pairsStrong and weak acids and the dissociation constant KaThe ionic product of water, KwpH of strong acids and strong basespH of weak acids from Ka and pKaTitration curvesHow buffer solutions workBuffer calculationsBuffers in living systems and industrySalt hydrolysis and the choice of indicator
Stereoisomerism
Aromaticity
Alcohols and Phenols
Aldehydes and Ketones
Topic overviewPreparing aldehydes and ketones by oxidation of alcoholsDistinguishing aldehydes and ketones with Tollens’ reagent and Fehling’s solutionReduction of aldehydes and ketones using NaBH₄Nucleophilic addition of HCN to aldehydes and ketonesReaction with 2,4-dinitrophenylhydrazineThe triiodomethane (iodoform) test
Carboxylic Acids and Their Derivatives
Topic overviewRelative acidity of carboxylic acids, phenols, alcohols and waterPreparing carboxylic acids by oxidationReduction and decarboxylation of carboxylic acidsAcid chlorides and their reactionsEsters and their hydrolysisAmides and their hydrolysisNitriles from carboxylic acids and halogenoalkanesHydroxynitriles, hydrolysis and reduction of nitriles
Amines
Amino Acids, Peptides and Proteins
Organic Synthesis and Analysis
Topic overviewPlanning a multi-step synthesisChoosing between alternative routesManipulation and separation techniquesPurification and melting temperatureAddition and condensation polymerisationPolyesters and polyamidesHigh resolution proton NMRCombining spectra to elucidate a structureInterpreting chromatographic dataGas chromatography and HPLC
Specified Practical Work
Topic overviewGravimetric analysis and qualitative analysis of unknown solutionsStandard solutions, standardising an acid and preparing a soluble saltBack titration and double titrationDetermining enthalpy changes by calorimetryFollowing a rate by gas collection, the iodine clock and reaction orderElectrochemical cells, redox titration and the estimation of copperDetermining an equilibrium constant and following a titration with a pH probeHydrolysis of 1-bromobutane and the preparation of an esterOrganic synthesis, purification and identification
Practical Skills and Techniques
Topic overviewChoosing apparatus and recording measurementsVolumetric technique with pipette, burette and volumetric flaskTitration procedure and the choice of indicatorHeating, heating under reflux and distillationFiltration, purification and qualitative testingMelting temperature, chromatography and electrochemical cellsVariables, errors and risk in evaluating a method
Mathematical Skills in Chemistry
Topic overviewStandard form, units and significant figuresRatios, fractions and percentagesChanging the subject and substituting valuesLogarithms, pH and pKaExponentials, the Arrhenius equation and rateGraphs, gradients and interceptsTangents and rates of changeArea under a curveUncertainty and combining errorsThe gas equation and equilibrium expressions
Bonding
- 8 subtopics
- 24 things to know
- Components 1 and 2
What Bonding covers
Bonding is examined in Components 1 and 2, since the Core Ideas are examined on both written papers, and drawn on again in Component 3. It covers ionic bonding and the formation of ions, covalent bonding and the balance of forces, coordinate bonding, electronegativity and bond polarity, the ionic–covalent continuum, intermolecular forces, permanent and temporary dipoles, hydrogen bonding and VSEPR and the shapes of simple molecules and ions.
Where it is assessed
Components 1 and 2
the Core Ideas, Principles and Concepts, which are examined on both written papers and drawn on again in Component 3.
Check the Eduqas specification ↗The 8 subtopics
Each one has its own page.
- Ionic bonding and the formation of ionsIonic bond, electron transfer that takes place when magnesium oxide is formed and giant ionic lattice.Open →
- Covalent bonding and the balance of forcesCovalent bond, double bond and triple bond.Open →
- Coordinate bondingCoordinate bond, how the ammonium ion is formed from ammonia and how the oxonium ion H₃O⁺ is formed.Open →
- Electronegativity and bond polarityTrend in electronegativity across a period, trend in electronegativity down a group and polar covalent bond.Open →
- The ionic–covalent continuumSaying that bonding is a continuum, polarisation of an anion and equivalent statement about covalent bonds approaching ionic character.Open →
- Intermolecular forces, permanent and temporary dipolesRecall questions on van der Waals forces and how a temporary dipole induces one in a neighbour, permanent dipole–dipole attraction, how each affects boiling temperature, why boiling point rises with the number of electrons, and comparing the three kinds of intermolecular force in strength.Open →
- Hydrogen bondingHydrogen bond, why ice is less dense than liquid water and biological consequence of ice being less dense than water.Open →
- VSEPR and the shapes of simple molecules and ionsRecall questions on counting electron pairs around a central atom, the greater repulsion of a lone pair, the linear, trigonal planar, tetrahedral and octahedral arrangements with their bond angles, the effect of a lone pair on the angle, and worked shapes for named molecules and ions.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
Aluminium chloride sublimes at about 180 °C whereas sodium chloride melts at 801 °C. Explain the difference.
Key term
Propanone and butane have almost the same relative molecular mass, yet propanone boils at 56 °C and butane at −1 °C. Explain why.
Key term
How does the polarity of a molecule affect the solvent in which it dissolves?
Key term
Ethanol boils at 78 °C but propane, of similar relative molecular mass, boils at −42 °C. Explain the difference.
Key term
Describe how the number of bonding and lone pairs on a central atom in an ion is worked out.
Key term
Define an ionic bond.
Key term
Explain how the ammonium ion is formed from ammonia.
Key term
Define electronegativity.
Key term
Why is the attraction in an ionic bond described as non-directional?
Key term
Which attractions and which repulsions are present in a covalent bond?
Key term
Why are all four N–H bonds in the ammonium ion identical?
Key term
Which is the most electronegative element, and what value is it given?
Key term
What is meant by saying that bonding is a continuum?
Key term
Why is hydrogen bonding restricted to compounds of nitrogen, oxygen and fluorine?
Evaluation
Place the three kinds of repulsion in order of decreasing strength.
Key term
Why do ionic compounds have high melting temperatures?
Key term
What determines the length of a covalent bond?
Key term
Explain the bonding when ammonia reacts with boron trifluoride.
Key term
Explain the trend in electronegativity down a group.
Key term
What is meant by the polarisation of an anion?
Key term
Which forces are overcome when a simple molecular substance boils?
Key term
Why is the boiling temperature of water so much higher than the trend from the other Group 6 hydrides would suggest?
Key term
What effect does each lone pair have on the bond angle?
Take Bonding further
The same content, four other ways.
Questions from this topic
Each one with the model answer underneath.
- 1
Define an ionic bond.
Model answer
An ionic bond is the strong electrostatic attraction between oppositely charged ions.
- 2
How are the ions in an ionic compound formed?
Model answer
One or more electrons are transferred from a metal atom to a non-metal atom, so that each ion is left with the stable electron arrangement of a noble gas.
- 3
Describe the electron transfer that takes place when magnesium oxide is formed.
Model answer
Magnesium loses its two 3s electrons to become Mg²⁺ and oxygen gains those two electrons to become O²⁻, so both end with the arrangement of neon.
- 4
Why is the attraction in an ionic bond described as non-directional?
Model answer
The electrostatic field around an ion acts equally in every direction, so the ion attracts all of its oppositely charged neighbours rather than being bonded to one particular partner.
- 5
What is a giant ionic lattice?
Model answer
It is a regular three-dimensional array in which every ion is surrounded by ions of opposite charge, repeating throughout the whole crystal.
- 6
Why do ionic compounds have high melting temperatures?
Model answer
A very large number of strong electrostatic attractions act throughout the lattice, so a great deal of energy is needed to separate the ions.
What is inside Levo
Six ways to work the same material.
Bonding revision questions
- What does Bonding cover in Eduqas A-Level Chemistry?
- 8 subtopics: ionic bonding and the formation of ions, covalent bonding and the balance of forces, coordinate bonding, electronegativity and bond polarity, the ionic–covalent continuum, intermolecular forces, permanent and temporary dipoles, hydrogen bonding and vsepr and the shapes of simple molecules and ions. Each one has its own page with questions and model answers.
- How is Bonding organised?
- By the Eduqas A410QS specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Bonding, 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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