Process
Edexcel A-Level Chemistry 9CH0
Atomic Structure and the Periodic Table
Bonding and Structure
Inorganic Chemistry and the Periodic Table
Topic overviewFlame tests and how they workThermal decomposition of nitrates and carbonatesCarrying out flame tests and testing the gasesGroup 2 elements and their compoundsTrends in Group 7 and predicting fluorine and astatineHalogen displacement reactionsDisproportionation and the reactions of chlorineHalides with concentrated sulfuric acid, and the hydrogen halidesTesting for halide ions with silver nitrateTesting for carbonate and hydrogencarbonate ionsTesting for sulfate and ammonium ions
Formulae, Equations and Amounts of Substance
Topic overviewThe mole, molar mass and empirical formulaThe ideal gas equation and molar volumeEquations, concentration and reacting quantitiesStandard solutions, titration and uncertaintyPercentage yield, atom economy and acid reactionsCore practicals 1 to 3Empirical formula and water of crystallisation by experimentApparatus, uncertainty and mathematical skills
Organic Chemistry I
Topic overviewFormulae, homologous series and functional groupsIUPAC nomenclatureTypes of organic reaction and structural isomerismStereoisomerism and E/Z nomenclaturePractical techniques in organic chemistryAlkanes, crude oil and combustion pollutantsRadical substitutionAlkenes, the double bond and hydrogenationElectrophilic addition, Markovnikov's rule and the test for an alkeneAddition polymers and waste polymersNucleophilic substitution of halogenoalkanesRates of hydrolysis and the SN1 and SN2 mechanismsClassifying and oxidising alcoholsAlcohols: practical techniques and the core practicals
Modern Analytical Techniques I
Energetics I
Kinetics I
Equilibrium I
Acid-Base Equilibria
Energetics II
Redox II
Transition Metals
Topic overviewElectron configuration and what makes a transition metalComplex ions, ligands and the colour of transition metal ionsCoordination number, monodentate ligands and the shapes of complexesBidentate and multidentate ligands, and ligand exchangeVanadium and chromium chemistryReactions with sodium hydroxide and ammoniaCobalt and copper complexesLigand exchange, amphoteric behaviour and the chelate effectTransition metals as catalysts
Kinetics II
Organic Chemistry II
Topic overviewChiralityAldehydes, ketones and their oxidationReduction and nucleophilic addition of HCNTesting for a carbonyl group: 2,4-DNPH and the iodoform reactionCarboxylic acids and their reactionsEsters and acyl chloridesReflux, extraction and recrystallisationDistillation, melting temperature and working safely
Organic Chemistry III
Topic overviewThe structure of benzene and the evidence for itElectrophilic substitution of benzeneNitration, halogenation, Friedel-Crafts and phenolAmines: structure and basicityReactions of amines and preparing themAmides and condensation polymersAmino acids, zwitterions and proteinsEmpirical and molecular formulae from analytical dataGrignard reagents and multi-step synthesisPurification techniques and the aspirin preparation
Equilibrium I
- 2 subtopics
- 8 things to know
- Papers 1 and 3
What Equilibrium I covers
Covers what makes an equilibrium dynamic, how Le Chatelier's principle predicts a shift, and the equilibrium constant Kc.
Where it is assessed
Papers 1 and 3
Advanced Inorganic and Physical Chemistry, then the synoptic paper.
Check the Pearson Edexcel specification ↗The 2 subtopics
Each one has its own page.
- Dynamic equilibrium and Le Chatelier's principleRecall questions on the conditions for dynamic equilibrium, on predicting a shift from a change in concentration, pressure or temperature, and on industrial compromise conditions.Open →
- The equilibrium constant KcWhat Kc describes, writing Kc expressions from equilibrium concentrations, including for N₂(g) + 3H₂(g) ⇌ 2NH₃(g), leaving pure solids and liquids out of heterogeneous equilibria, and working out the units of Kc.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Process
How is Kc written and what does its size mean?
Key term
What does it mean for an equilibrium to be dynamic?
Numbers
For the equilibrium N₂(g) + 3H₂(g) ⇌ 2NH₃(g), write the Kc expression.
Key term
What is meant by a reversible reaction?
Key term
What does the equilibrium constant Kc describe?
Key term
Why is the equilibrium described as dynamic rather than static?
Key term
For the reaction aA + bB ⇌ cC + dD, write the expression for Kc.
Take Equilibrium I further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Dynamic equilibrium vs Static equilibrium
Dynamic equilibrium: opposing reactions continuing at equal rates in a closed system. Static equilibrium: state with no continuing opposing reactions.
Equilibrium position vs Equilibrium constant
Equilibrium position: relative amounts of reactants and products at equilibrium. Equilibrium constant: value calculated from equilibrium concentrations at a stated temperature.
Closed system vs Open system
Closed system: matter cannot enter or leave the vessel. Open system: matter can enter or leave the vessel.
Questions from this topic
Each one with the model answer underneath.
- 1
What is meant by a reversible reaction?
Model answer
A reaction that can proceed in both the forward and backward directions.
- 2
What is meant by dynamic equilibrium?
Model answer
In a closed system, the point at which forward and reverse reactions run at matching rates, so no concentration changes any further.
- 3
At dynamic equilibrium, how do the rates of the forward and backward reactions compare?
Model answer
They are equal.
- 4
Once dynamic equilibrium is reached, how do the concentrations behave?
Model answer
They remain constant.
- 5
Why is the equilibrium described as dynamic rather than static?
Model answer
The forward and backward reactions continue to occur, even though the concentrations no longer change.
- 6
What type of system is required for a reaction to reach equilibrium?
Model answer
A closed system, where no reactants or products can enter or leave.
What is inside Levo
Six ways to work the same material.
Equilibrium I revision questions
- What does Equilibrium I cover in Edexcel A-Level Chemistry?
- 2 subtopics: dynamic equilibrium and le chatelier's principle and the equilibrium constant kc. Each one has its own page with questions and model answers.
- How is Equilibrium I organised?
- By the Edexcel 9CH0 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Equilibrium I, 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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