AQA GCSE CHEMISTRY CHEMICAL ANALYSIS QUESTIONS WITH CORRECT ANSWERS 2025

AQA GCSE CHEMISTRY: CHEMICAL ANALYSIS
QUESTIONS WITH CORRECT ANSWERS 2025
WhatBisBaB'pure'Bsubstance,BinBchemistry?B-BCORRECTBANSWERB--
BaBpureBsubstanceBisBaBsingleBelementBorBcompound,BnotBmixedBwithBanotherBsubstance




WhatB2BpiecesBofBdataBcanBweBuseBtoBdetermineBifBaBsubstanceBisBpure,Bwhy?B-BCORRECTBANSWERB--
BpureBelementsBandBcompoundsBMELTBandBBOILBatBspecificBtemperaturesB=>BMELTINGBPOINTBandBBOILIN

GBPOINTBdataBcanBbeBusedBtoBdistinguishBpureBsubstancesBfromBmixtures



FromBaBheatingBgraph,BhowBcanBweBknowBifBaBsubstanceBisBpure?B-BCORRECTBANSWERB--
BifBtheBmeltingBpointBandBboilingBpointBlinesBareBstraighBandBhorizontal



-BandBifBtheseBtemperaturesBmatchBtheBrealBtemperaturesBfromBtheBinternet



FromBaBheatingBgraph,BhowBcanBweBknowBthatBaBsubstanceBisimpure?B-BCORRECTBANSWERB--
BifBtheBmeltingBpointBandBboilingBpointBareBnotBstraightBandBcompletelyBhorizontal



(theBsubstanceBmeltsBandBboilsBoverBaBrangeBofBtemperatures)

-BmoreBthanBoneBvalueBforBtheBmelting/boilingBpoint)



InBeverydayBlanguage,BwhatBisBaB'pure'Bsusbtance?B-BCORRECTBANSWERB--
BaBpureBsubstanceBinBthisBcontextBcanBmeanBanythingBthatBhasBhadBnothingBaddedBtoBit,BsoBitBisBunadultera

tedBandBinBitsBnaturalBstate,Beg.BpureBmilk



WhatBisBaBformulation?B-BCORRECTBANSWERB--
BaBcomplexBmixtureBthatBhasBbeenBdesignedBasBaBusefulBproduct




HowBareBformulationsBmade?B-BCORRECTBANSWERB--
BformulationsBareBmadeBbyBmixingBtheBcomponentsBinBcarefullyBmeasuredBquantitiesBtoBensureBthatBtheBp

roductBhasBtheBrequiredBproperties



GiveB7BexamplesBofBformulations.B-BCORRECTBANSWERB--Bfuels

-BcleaningBagents

-Bpaints

, -Bmedicines

-Balloys

-Bfertilisers

-Bfoods



WhyBisBchromatographyBused?B-BCORRECTBANSWERB--
BchromatographyBcanBbeBusedBtoBseparateBmixturesBandBgiveBinformationBtoBhelpBidentifyBsubstances



-BpaperBchromatographyBallowsBusBtoBseparateBsubstancesBbasedBonBtheirBdifferentBSOLUBILITIES



WhatBisBtheBmethodBforBanyBgeneralBpaperBchromatographyBexperiment?B-BCORRECTBANSWERB-
1)BTakeBaBpieceBofBspecialBchromatographyBpaper.

2)BDrawBaBhorizontalBpencilBlineB2cmBup.

3)BPutBaBdotBofBtheBfirstBcolourBonBtheBpencilBlineBandBotherBdotsBalongBtheBlineBforBanyBotherBcoloursB(spa
ceBthemBout).

4)BPlaceBtheBbottomBofBtheBpaperBinBaBsolventB(aBliquidBthatBwillBdissolveBsubstances)B(notBaboveBtheBpenc
ilBline).



WhatBisBtheBstationaryBphaseBinBchromatography?



WhatBisBtheBmobileBphaseBinBchromatography?B-BCORRECTBANSWERB--
BtheBstationaryBphaseBisBtheBpaperBbecauseBitBdoesBnotBmove




-BtheBmobileBphaseBisBtheBsolventBbecauseBitBdoesBmove



HowBcanBweBidentifyBaBpureBsubstanceBfromBanBimpureBsubstanceBafterBcarryingBoutBpaperBchromatograp
hy?B-BCORRECTBANSWERB--BaBpureBchemicalBwillBproduceBaBsingleBspotBinBALLBsolvents



-BanBimpureBsubstanceBmayBseparateBintoBdifferentBspotsBDEPENDINGBonBtheBsolvent



HowBdoesBpaperBchromatographyBwork?B-BCORRECTBANSWERB--
BeachBchemicalBinBtheBmixtureBwillBbeBattractedBtoBtheBstationaryBphaseBtoBaBdifferentBextentB(chemicalsBt

hatBareBweaklyBattractedBwillBmoveBfurtherBupBtheBpaper)