Key term
OCR A-Level Chemistry H432
Foundations in Chemistry
Topic overviewAtomic structure, isotopes and counting sub-atomic particlesRelative isotopic, atomic, molecular and formula massPredicting ionic charges and the common ionsWriting formulae, balanced equations and ionic equationsThe mole, molar mass and the Avogadro constantEmpirical and molecular formulae, and hydrated saltsGas volumes, concentration and the ideal gas equationStoichiometry, percentage yield and atom economyApparatus, and why high atom economy mattersMathematical skills and measuring mass, volume and gasAcids, alkalis, dissociation and neutralisationPreparing a standard solutionCarrying out a titration and its calculationsPlanning an experiment: variables, apparatus and recording resultsPractical safety, heating and filtrationUncertainty, percentage error, precision and accuracyEvaluating results: anomalies, conclusions, limitations and improvementsAssigning oxidation numbersRoman numerals in names, and the chlorate and nitrate ionsOxidation, reduction and metals reacting with acidsRedox equations and identifying what is oxidisedShells, orbitals and sub-shellsThe order in which sub-shells fillWriting electron configurations for atoms and ions
Bonding and Structure
Topic overviewIonic bonding and the properties of ionic compoundsCovalent and coordinate bondingLone pairs, bonding pairs and average bond enthalpyElectron pair repulsion theory, linear and trigonal planar shapesTetrahedral, pyramidal and non-linear shapes and their bond anglesOctahedral shapes, ions, and drawing molecules in three dimensionsElectronegativity, polar bonds and polar moleculesPermanent and induced dipoles, and hydrogen bondingSimple molecular lattices and why they melt easilySolubility and conductivity of simple molecular compounds
Periodic Table and Energy
Topic overviewPeriodicity and the electron configurations of periods 2 and 3The blocks, and first and successive ionisation energiesMetallic and giant covalent structures and their propertiesGroup 2 reactions with oxygen, water and acidsIonisation energy down Group 2 and the alkalinity of the hydroxidesUses of Group 2 compounds in agriculture and medicineThe halogens: boiling points, London forces and reactivityHalogen displacement reactions and the colours seenDisproportionation and the chlorination of waterTesting for halide ions with silver nitrate and ammoniaTesting for carbonate, sulfate and halide ionsTesting for ammonium ions and the order of the testsConcentration, pressure and measuring reaction rateCatalysts and their industrial importanceThe Boltzmann distribution, temperature and catalysts
Enthalpy Changes
Topic overviewExothermic and endothermic reactions and enthalpy profilesStandard conditions and the standard enthalpy changesBond enthalpies, q = mcΔT and calorimetryCalculating enthalpy change from bond enthalpiesWhy average bond enthalpies give only an approximationHess' law and enthalpy cycles from combustion and formation dataWorking through an enthalpy cycle and the sign conventionsCalorimetry and correcting for heat loss
Chemical Equilibrium
Basic Concepts of Organic Chemistry
Topic overviewIUPAC nomenclature and the alkyl groupsGeneral, structural, displayed and skeletal formulaeHomologous series, functional groups and saturationStructural isomers, bond fission and curly arrowsChain, position and functional group isomerismCurly arrows, homolytic and heterolytic fissionNucleophiles, electrophiles, radicals and the mechanism steps
Core Organic Chemistry
Topic overviewAlkanes: bonding, shape and boiling pointsCombustion of alkanes and their reaction with halogensThe radical substitution mechanism and its limitationsAlcohols: polarity, solubility and classificationOxidation, dehydration and substitution reactions of alcoholsHydrolysis of haloalkanes and comparing the ratesNucleophilic substitution and carbon-halogen bond strengthCFCs, radicals and the catalytic destruction of ozoneCombining analytical techniques to identify a compound
Alkenes
Topic overviewAlkenes: the double bond, sigma and pi bonding, and shapeE/Z and cis-trans isomerism in alkenesHydrogenation, halogenation and hydration of alkenesElectrophilic addition, carbocation stability and Markownikoff's ruleAddition polymerisation and repeat unitsWaste polymers, and biodegradable and photodegradable alternatives
Organic Synthesis
How Fast?
Topic overviewRate equations, order and the rate constantDeducing orders and finding the units of kWhat the rate equation reveals about the mechanismConcentration-time graphs and continuous monitoringHalf-life and the rate constant of a first-order reactionRate-concentration graphs and the initial rates methodClock reactions, colorimetry and analysing kinetic graphsThe rate-determining step and testing a proposed mechanismTemperature, the rate constant and the Arrhenius equationThe ln k against 1/T graph and finding the activation energy
Physical Chemistry and Transition Elements
Topic overviewMole fraction, partial pressure and ICE tablesKc and Kp expressions, their units and calculationsWhat changes the equilibrium constant, and the reaction quotientLattice enthalpy and the Born-Haber cycleEnthalpy of solution and hydration, and the effect of ionic charge and sizeEntropy and calculating entropy changeGibbs free energy and thermodynamic feasibility
Acids, Bases and Buffers
Topic overviewBrønsted-Lowry acids and bases and their reactionsKa, pKa, pH and the ionic product of waterCalculating the pH of strong acids, strong bases and weak acidspH and hydrogen ion concentrationWhat a buffer is and how it resists a change in pHBuffer calculations and the buffer that controls blood pHTitration curves, choosing an indicator and using a pH meterpH titration curves for the four acid-base combinationsHow an indicator works and choosing the right one
Redox and Electrode Potentials
Topic overviewOxidising and reducing agents, and balancing half-equationsCombining half-equations and using oxidation numbersRedox titrations and their calculationsStandard electrode potentials and setting up half-cellsThe electrochemical series and predicting feasibilityStorage cells and fuel cells
Transition Elements
Topic overviewLigands, complex ions and coordination numberElectron configurations from Sc to Zn, and which are transition elementsVariable oxidation states, coloured ions and catalysisThe shapes of complexes, stereoisomerism and cisplatinLigand substitution, haemoglobin and the copper complexesHydroxide precipitates of iron, manganese and chromiumRedox interconversions of iron, chromium and copperWhy ligand substitution happens and the changes it causesPrecipitation reactions written as aqua complexesDissolving hydroxides in excess ammonia and distinguishing the ions
Aromatic Compounds
Topic overviewThe delocalised model of benzene and the evidence for itNitration, halogenation and Friedel-Crafts reactions of benzeneThe reactions of phenol, and directing effectsElectrophilic substitution and directing effectsPhenol: acidity, bromination and nitrationWhy phenol is more reactive than benzene, and planning a synthesis
Organic Chemistry and Analysis
Topic overviewOxidation and reduction of carbonyls, and the addition of HCNThe nucleophilic addition mechanism2,4-DNPH and Tollens' reagentCarboxylic acids: solubility and reactions with metals, carbonates and basesEsterification and the hydrolysis of estersAcyl chlorides and their reactions with alcohols, amines and ammoniaAmines as bases, and preparing aliphatic aminesSecondary and tertiary amines, and preparing aromatic aminesAmino acids, their reactions, and amidesOptical isomerism and identifying a chiral centreCondensation polymerisation and the ester and amide linkagesHydrolysing condensation polymers and telling them from addition polymersNitriles from haloalkanes and from carbonyl compoundsFriedel-Crafts reactions and lengthening the carbon chainThin-layer and gas chromatography, Rf values and retention timesTest-tube tests for the organic functional groupsTests for the inorganic ions and interpreting chromatograms
Spectroscopy
Topic overviewCarbon-13 and proton NMR: peaks, chemical shift and integrationSpin-spin splitting and predicting a spectrumTMS, deuterated solvents and the D₂O shakeCombining elemental analysis, mass spectrometry, IR and NMRMolecular formula from the molecular ion, and fragmentation lossesWhat IR and NMR each contribute to a structureInfrared absorption, global warming and breathalysersA systematic approach and the degree of unsaturation
Organic Chemistry and Analysis
- 17 subtopics
- 32 things to know
- Components 02 and 03
What Organic Chemistry and Analysis covers
The second half of the organic course: carbonyl compounds and nucleophilic addition, carboxylic acids, esters and acyl chlorides, amines, amino acids and chirality, condensation polymers, carbon-carbon bond formation, and the chromatographic and test-tube analysis that identifies the product.
Where it is assessed
Components 02 and 03
Synthesis and Analytical Techniques, then the unified paper.
Check the OCR specification ↗The 17 subtopics
Each one has its own page.
- Oxidation and reduction of carbonyls, and the addition of HCNRecall questions on [O] and [H] notation, oxidising an aldehyde, reducing an aldehyde and a ketone with NaBH₄, and the hydroxynitrile from HCN.Open →
- The nucleophilic addition mechanismRecall questions on why the carbonyl carbon is electrophilic, the hydride and cyanide attacks, the intermediate formed, and the protonation that completes it.Open →
- 2,4-DNPH and Tollens' reagentRecall questions on what each reagent detects, the observations for a positive result, using a 2,4-DNPH derivative to identify a specific compound, and why ketones fail Tollens'.Open →
- Carboxylic acids: solubility and reactions with metals, carbonates and basesRecall questions on the hydrogen bonding that makes them soluble, and on the products with reactive metals, carbonates, metal oxides and alkalis.Open →
- Esterification and the hydrolysis of estersRecall questions on the acid catalyst and reversibility of esterification, the acid anhydride route, and the products of acid and of base hydrolysis.Open →
- Acyl chlorides and their reactions with alcohols, amines and ammoniaRecall questions on making an acyl chloride with thionyl chloride, and on the products with water, alcohols, primary and secondary amines and ammonia.Open →
- Amines as bases, and preparing aliphatic aminesRecall questions on why the nitrogen lone pair makes an amine basic, the salt formed with an acid, and preparing a primary amine from a haloalkane with excess ammonia.Open →
- Secondary and tertiary amines, and preparing aromatic aminesRecall questions on further substitution to secondary and tertiary amines, and on reducing a nitroarene with tin and hydrochloric acid to give phenylamine.Open →
- Amino acids, their reactions, and amidesRecall questions on the general formula of an α-amino acid, its reactions with alkali, acid and alcohols, and the structures of primary and secondary amides.Open →
- Optical isomerism and identifying a chiral centreRecall questions on what optical isomerism is, non-superimposable mirror images, locating a chiral centre, and why glycine is the exception.Open →
- Condensation polymerisation and the ester and amide linkagesRecall questions on what is eliminated, which pairs of monomers give a polyester and which a polyamide, and what changes when acyl chlorides are used.Open →
- Hydrolysing condensation polymers and telling them from addition polymersRecall questions on the products of acid and base hydrolysis of a polyester and a polyamide, and on identifying which kind of polymer a structure is.Open →
- Nitriles from haloalkanes and from carbonyl compoundsRecall questions on the cyanide substitution and addition routes, the mechanisms each follows, and reducing or hydrolysing the nitrile afterwards.Open →
- Friedel-Crafts reactions and lengthening the carbon chainRecall questions on the reagents and halogen carriers for alkylation and acylation, and on how many carbons each route adds to the chain.Open →
- Thin-layer and gas chromatography, Rf values and retention timesRecall questions on calculating and using Rf values, retention time, what a peak area represents, and building an external calibration curve.Open →
- Test-tube tests for the organic functional groupsRecall questions on the tests for alkenes, haloalkanes, phenols, carbonyls, aldehydes against ketones, alcohols and carboxylic acids.Open →
- Tests for the inorganic ions and interpreting chromatogramsRecall questions on the tests for carbonate, sulfate, the halides and ammonium, and on reading retention times and peak areas from a chromatogram.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Process
What happens to the π bond during nucleophilic addition to a carbonyl, what intermediate forms, and which reagent detects a carbonyl group?
Key term
What is a positive 2,4-DNPH result, and how is the precipitate used to identify a specific carbonyl compound?
Key term
What is Tollens' reagent and what complex ion does it contain?
Key term
What observation indicates a positive Tollens' test?
Numbers
Which part of the carboxyl group donates and which accepts a hydrogen bond, and why are carboxylic acids soluble in water?
Numbers
What are the general equations for a carboxylic acid reacting with magnesium, with sodium carbonate and with sodium hydroxide?
Numbers
What is eliminated when a carboxylic acid reacts with an alcohol to form an ester, what forms when an acid anhydride reacts with an alcohol, and what is the general equation?
Numbers
Why does base hydrolysis of an ester go to completion, what is the equation for a carboxylic acid with thionyl chloride, and what forms when an acyl chloride reacts with an alcohol?
Numbers
Write the general equation for the hydrolysis of an acyl chloride.
Key term
What type of ester is formed when phenol reacts with an acyl chloride?
Process
Why can the nitrogen of an amine act as a base, and what bond forms when it accepts a proton?
Process
What reagents prepare a primary amine from a haloalkane, what becomes of the hydrogen halide, and why is excess ammonia used?
Numbers
Write the equation for the reduction of nitrobenzene to phenylamine using [H] notation.
Process
What happens to the carboxylic acid group of an amino acid with an alkali, what forms, and how does an amino acid form an ester with an alcohol?
Key term
What is produced when the amine group of an amino acid reacts with an acid, and what are the structures of a primary and a secondary amide?
Key term
What is optical isomerism, what structural feature causes it, and what is a chiral centre?
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After locating a carbon atom, what must you check to determine if it is a chiral centre?
Key term
Which groups form the ester and amide linkages, and what changes when acyl chlorides are used as monomers?
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What products are formed when a polyester undergoes acid hydrolysis?
Numbers
How can you identify that a polymer is an addition polymer rather than a condensation polymer?
Process
Which reagents turn a haloalkane into a nitrile, what mechanism does the reaction follow, and what is displaced?
Process
By what mechanism does a carbonyl compound react with HCN, what happens after the cyanide ion attacks the carbonyl carbon, and which reagents reduce a nitrile to an amine?
Key term
What is a halogen carrier, what reagents are needed for Friedel–Crafts alkylation, and what bond does Friedel–Crafts alkylation form?
Key term
What reagents are required for Friedel–Crafts acylation?
Numbers
What does the area under a gas chromatogram peak represent, how is percentage composition calculated, and what is the percentage composition for a peak area of 3470 out of a total of 4250?
Numbers
How is an external calibration curve built and used in gas chromatography, and what is retention time?
Key term
How are haloalkanes identified, and what colour precipitates do a chloroalkane and an iodoalkane give with silver nitrate?
Process
What species is present in Tollens' reagent, how does acidified potassium dichromate test alcohols, and what happens when an aldehyde is warmed with acidified potassium dichromate?
Key term
Describe the test-tube test to identify the carbonate ion (CO₃²⁻).
Key term
How are retention times used when interpreting a gas chromatogram?
Numbers
State the chromatographic retention-factor equation.
Take Organic Chemistry and Analysis further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Aldehyde vs Ketone
Aldehyde: a carbonyl compound with the functional group at a chain end. Ketone: a carbonyl compound with the functional group within a chain.
Stationary phase vs Mobile phase
Stationary phase: the phase remaining fixed during separation. Mobile phase: the phase moving through or over the fixed phase.
Questions from this topic
Each one with the model answer underneath.
- 1
What reagent is used to oxidise aldehydes to carboxylic acids?
Model answer
Acidified potassium dichromate (K₂Cr₂O₇/H₂SO₄)
- 2
In organic redox equations, what does the symbol [O] represent?
Model answer
An oxidising agent
- 3
In organic redox equations, what does the symbol [H] represent?
Model answer
A reducing agent
- 4
Which ion acts as the oxidising agent when aldehydes are oxidised in acidic solution?
Model answer
The dichromate ion, Cr₂O₇²⁻
- 5
What type of reaction mechanism does NaBH₄ use to reduce carbonyl compounds to alcohols?
Model answer
Nucleophilic addition
- 6
What type of alcohol is formed when an aldehyde is reduced by NaBH₄?
Model answer
A primary alcohol
What is inside Levo
Six ways to work the same material.
Organic Chemistry and Analysis revision questions
- What does Organic Chemistry and Analysis cover in OCR A-Level Chemistry?
- 17 subtopics: oxidation and reduction of carbonyls, and the addition of hcn, the nucleophilic addition mechanism, 2,4-dnph and tollens' reagent, carboxylic acids: solubility and reactions with metals, carbonates and bases, esterification and the hydrolysis of esters, acyl chlorides and their reactions with alcohols, amines and ammonia, amines as bases, and preparing aliphatic amines, secondary and tertiary amines, and preparing aromatic amines, amino acids, their reactions, and amides, optical isomerism and identifying a chiral centre, condensation polymerisation and the ester and amide linkages, hydrolysing condensation polymers and telling them from addition polymers, nitriles from haloalkanes and from carbonyl compounds, friedel-crafts reactions and lengthening the carbon chain, thin-layer and gas chromatography, rf values and retention times, test-tube tests for the organic functional groups and tests for the inorganic ions and interpreting chromatograms. Each one has its own page with questions and model answers.
- How is Organic Chemistry and Analysis organised?
- By the OCR H432 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Organic Chemistry and Analysis, on a schedule.
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