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AQA AS-Level Chemistry 7405
Atomic Structure
Topic overviewFundamental ParticlesMass Number and IsotopesTime of Flight Mass Spectrometry: Ionisation and AccelerationTime of Flight Mass Spectrometry: Drift, Detection and Calculating m/zElectron Configuration: Sub-shells and OrbitalsElectron Configuration: Writing Configurations for Atoms and IonsIonisation Energies and Periodic Trends
Amount of Substance
Topic overviewRelative Atomic and Molecular MassThe Mole and the Avogadro ConstantThe Ideal Gas EquationEmpirical and Molecular FormulaBalanced Equations and Reaction CalculationsAtom Economy and Percentage YieldAcid-Base Titrations: Principles, Indicators and ApparatusAcid-Base Titrations: Standard Solutions and Calculations
Bonding
Topic overviewIonic BondingCovalent, Dative Covalent and Metallic BondingCrystal Structures: Giant Ionic Lattices and DiamondCrystal Structures: Graphite and Simple Molecular SolidsShapes of Molecules and Ions: VSEPR and Electron Pair RepulsionShapes of Molecules and Ions: Predicting Shapes and Bond AnglesElectronegativity and Bond PolarityIntermolecular Forces
Energetics and Thermodynamics
Kinetics
Chemical Equilibria
Redox and Electrochemistry
Periodicity and Group Chemistry
Topic overviews, p, d and f Block ClassificationTrends in Period 3Group 2 Trends in Atomic Radius, Ionisation Energy and Melting PointReactions of Group 2 with WaterSolubility Trends of Group 2 HydroxidesSolubility Trends of Group 2 SulfatesUses of Group 2 CompoundsTest for Sulfate IonsTrends in Electronegativity and Boiling Point of HalogensHalogens as Oxidising Agents and Displacement ReactionsHalide Ions as Reducing Agents: Chloride and BromideHalide Ions as Reducing Agents: Iodide, and the EquationsTest for Halide Ions Using Silver NitrateTests for Ammonium, Group 2, Hydroxide and Carbonate IonsReactions of Chlorine with WaterReactions of Chlorine with Cold Dilute NaOH and Water Treatment
Introduction to Organic Chemistry
Hydrocarbons
Topic overviewAlkanes, Fractional Distillation and CrackingCombustion of Alkanes and PollutantsFree Radical Chlorination of AlkanesAlkenes: Structure, Bonding and Electrophilic AdditionMarkovnikov's Rule and Carbocation StabilityAddition Polymers and Repeating UnitsProperties and Uses of Polyalkenes
Halogenoalkanes, Alcohols and Organic Analysis
Topic overviewNucleophilic Substitution of HalogenoalkanesEffect of Bond Enthalpy on Reaction RateElimination Reactions and Competing MechanismsCFCs and Ozone DepletionIndustrial Production of AlcoholsBiofuels and Carbon NeutralityClassification and Oxidation of AlcoholsDistinguishing Aldehydes and KetonesElimination of Water from AlcoholsTest-Tube Reactions for Functional GroupsMass Spectrometry and Molecular FormulaInfrared Spectroscopy, Functional Groups and Global Warming
Redox and Electrochemistry
- 3 subtopics
- 21 things to know
- Papers 1 and 3
What Redox and Electrochemistry covers
Redox and electrochemistry is examined on Papers 1 and 3. It begins with oxidation states and half-equations, then uses standard electrode potentials to predict which reactions run and to explain the cells that put them to work.
Where it is assessed
Papers 1 and 3
Inorganic and physical chemistry, then the synoptic paper.
Check the AQA specification ↗The 3 subtopics
Each one has its own page. AQA AS Chemistry students sit this topic in the first year.
- Redox: Definitions and the Rules for Oxidation StatesOxidation and reduction in terms of electrons, oxidising and reducing agents, and the rules for assigning oxidation states.Open →
- Redox: Identifying Oxidation and Reduction in a ReactionReading oxidation state changes off an equation, and building half-equations into a balanced overall equation.Open →
- Half-Equations and Combined Redox EquationsWriting half-equations and combining them into a balanced overall equation.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
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By IUPAC convention, which side of a half-equation holds the more reduced form, and which electrodes are written on the left and on the right of a cell?
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What is oxidation defined as in terms of electrons?
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What change in oxidation state indicates that an element has been oxidised?
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What change in oxidation state indicates that an element has been reduced?
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What is a half-equation in the context of redox reactions?
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When writing a half-equation, what must be balanced in addition to atoms?
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What are the standard conditions for measuring standard electrode potential, E°?
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What concentration of ions is specified for standard electrode potential measurements?
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In a half-equation written to the IUPAC convention, which side carries the more reduced form and which side carries the electrons?
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Given E°(Cl₂/Cl⁻) = +1.36 V and E°(Br₂/Br⁻) = +1.09 V, which is the stronger oxidising agent, chlorine or bromine?
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Given E°(Zn²⁺/Zn) = −0.76 V and E°(Fe²⁺/Fe) = −0.44 V, which metal is the stronger reducing agent, zinc or iron?
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What is the half-equation for the positive electrode reaction in a lithium cell?
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What is the half-equation for the negative electrode reaction in a lithium cell?
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What is reduction defined as in terms of electrons?
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In a redox reaction, how can you identify which element has been oxidised?
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When combining half-equations, what must happen to the electrons?
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What is the IUPAC convention for writing half-equations for electrode reactions?
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In the conventional representation of a cell, which electrode is written on the left?
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Given E°(Cu²⁺/Cu) = +0.34 V and E°(Zn²⁺/Zn) = −0.76 V, what is the EMF for the reaction Zn + Cu²⁺ → Zn²⁺ + Cu?
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What are the three categories of commercial electrochemical cells based on their rechargeability?
Take Redox and Electrochemistry further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Oxidation vs Reduction
Oxidation: electron loss or an increase in oxidation number. Reduction: electron gain or a decrease in oxidation number.
Oxidising agent vs Reducing agent
Oxidising agent: a species accepting electrons and becoming reduced. Reducing agent: a species donating electrons and becoming oxidised.
Anode vs Cathode
Anode: electrode where oxidation occurs. Cathode: electrode where reduction occurs.
Questions from this topic
Each one with the model answer underneath.
- 1
What is oxidation defined as in terms of electrons?
Model answer
Oxidation is the loss of electrons
- 2
What is reduction defined as in terms of electrons?
Model answer
Reduction is the gain of electrons
- 3
What is an oxidising agent in terms of electron transfer?
Model answer
An oxidising agent is an electron acceptor
- 4
What is a reducing agent in terms of electron transfer?
Model answer
A reducing agent is an electron donor
- 5
What oxidation state is assigned to uncombined elements?
Model answer
Zero
- 6
What oxidation state is assigned to a simple monatomic ion?
Model answer
Equal to the charge on the ion
What is inside Levo
Six ways to work the same material.
Redox and Electrochemistry revision questions
- Is Redox and Electrochemistry examined at AS in AQA Chemistry?
- Yes. It sits in Papers 1 and 3, 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 Redox and Electrochemistry cover in AQA AS-Level Chemistry?
- 3 subtopics: redox: definitions and the rules for oxidation states, redox: identifying oxidation and reduction in a reaction and half-equations and combined redox equations. Each one has its own page with questions and model answers.
- How is Redox and Electrochemistry organised?
- By the AQA 7405 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Redox and Electrochemistry, 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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