7/24/2019 AQA A level Chemistry Unit 4 Definitions

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Nucleophile: Electron pair donor.Electrophile: Electron pair acceptor.Reagent: Chemical/chemicals that reactwith an organicmolecule.Substrate: The organicmoleculethat undergoes the reaction.Addition Reacton: An unsaturatedmolecule (alkene becomes saturated.Elimination Reaction: Saturated(alkane becomes unsaturated.Substitution Reaction: Saturated(alkane remains saturated! condition: a"ueousreagent.#ase: Curl$ arrow beginshere but goes to %$drogen! condition: alcoholicreagent.&$namic E"uilibrium: 'orwardsand backwardsreactions proceeding at e"ualrateswith the

concentration o reactants and products as constant.)e Chatelier*s +rinciple: , we change the e-ternalconditiono a reaction at e"uilibrium! the

position o e"uilibriumwill moeso as to opposethe e-ternal change.Actiation Energ$ (Ea: The minimumenerg$the collidingparticlesmust hae or a

chemical reaction to occur.ost +robable Energ$ (Emp: This is the hump that takes place on the a-well&istribution

0raph.Catal$st: 1hat: A substance which speedsup a chemical reaction but remains chemicall$

unchangedb$ the reaction.%ow: A catal$st proides an alternatiereaction pathwa$o loweractiationenerg$.

Reaction Rate: Change in concentrationo a substance in a unit o time.Reagent o 2-idating Alcohols: Aci3ed +otassium &ichromate (orange

+roduct o 2-idating Alcohols: Cr45

(green6it is an o-idisingagent! thereore it is reduced.#io6'uels: 'uel produced rom biologicalor renewablesources.Carbon Neutral: Nonet increaseto the C27leel in the atmosphere+ol$merisation: Reaction which turns man$ small molecules into long chain molecules.%ow isomers ound in ,na6red Spectrum: 'inger print region uni"ueto all compounds

comparisonto authentic sample.+rimar$ Alcohols: 2-idisedto Aldeh$des! then to Carbo-$licAcid.Seconda$ Alcohols: 2-idisedto 8etones.Reducing Agents: 0ains 2-$gen! )oses Electrons! )oses %$drogen.2-idising Agents: )oses o 2-$gen! 0ains o Electrons! 0ains %$drogen.Stereoisomerism: Compoundswith the same structuralormulawith bonds arranged

di9erentl$ in space.

Structural ,somers: %ae the same molecular ormulabut di9erent structural ormulae.+osition ,somers: %ae samemolecularormulabut di9erent structures due to di9erent

positionso the sameunctional groupon the same carbon chainChain ,somers: Structural isomerswhich occur when there is more than one wa$ o

arranging the carbon skeleton o a molecule%$drol$sis: Splitting C6 bondsusing waterolecular ,on: The moleculewith an electronknocked o9Radical: An unpairedelectron.Substitution: Replacement o the %alogen.Racemic i-ture: A mi-ture containing e"ualamountso both enantiomersp%: 6log;

Transesteri3cation: A reersiblereactionin which an esterreacts with an alcohol! usuall$ ine-cess! to orm a newesterand a newalcohol+lasticiser: A substance used to sotenplastic and increase ?e-ibilit$Ac$lium Cation: The electrophile R65C2#u9er Solution: A solution that resistschanges in p% on addition o smallamounts o acid

or baseor on dilution#u9er Region: Concentrationrange oer which a weak acid/base can show bu9er action#u9er Range: p%range oer which weak acid/bu9er can show bu9er action+ol$merisation: The @oining o smallmoleculesto orm largemoleculesEnantiomers: Three6dimensional! non6superimposablemolecular structure mirror imagesChromatograph$: Techni"ue or separatingthe components o a mi-ture on the basis o

di9erences in their anitiesor a stationar$and or a moingphase.

%omogenous: All reactants in the samephase%omologous Series: A group o compounds that hae similar propertiesand share a general

ormulasuch as Cn%7n57Strong: 'ull$dissociates in a"ueous solution1eak: +artiall$dissociates in a"ueous solution