IntroductionSodaash,orsodiumcarbonate,isacommonlyusedneutralizingagent,suchasineliminatingcorrosionandtocontrolpHinwatertreatment.Itisalsoanessentialrawmaterialinglass,detergents,andotherindustrialproducts.Likemostchemicalsubstances,sodaashisusuallynotfoundinitspureform,sodiumcarbonateorNa2CO3,asittendstoalsohavesmallamountsofNaOHandNaHCO3present.1Forthisreason,determiningthetotalamountofsodiumcarbonateinsolutionrequiresaspecificprocedure.Amajoraspectofanalyticalchemistryisbeingabletofindtheconcentrationofanunknownsample.Therearevariouswaysofdoingso,includingchromatography,spectrometry,absorption,pH,ortitrations.Forthislab,titrationsareperformedinordertofindtheconcentrationoftheunknownsamples.Thepurposeofatitrationistouseaknownconcentrationofasubstanceinordertofindtheequivalencepointofaknownorunknownanalyte,thusbeingabletofinditsconcentration.Astheunknownsampleinthisexperimentissodaash,atitrationmustbepreparedappropriatelyfortheanalyte.Becausesodaashisaweakbase,itwouldprovebeneficialtouseastrongacidasthetitrant,suchasHCl,asastrongacidandweakbasereactwell.Alongwithagoodtitrant,aproperindicator,withthecorrectpHrangemustbechosen.Sodiumbicarbonatecoupledwithastrongacid,suchasHClhastwoequivalencepoints,thefirstbeingtheconversiontobicarbonate,andthesecondtocarbonicacid.2ThefirstequivalencepointoccursatapHofabout8.0andthesecondatapHofabout4.0,makingphenolphthaleinandscreenedmethylorangegoodindicatorsforthetworeactions,respectively.(1)DeterminationoftheCarbonateContentofaSoda-AshSamplehttps://chem.libretexts.org/@go/page/75254(accessedSep29,2021).(2)Jacobs,A.Neutralization Titrations:DeterminationofSodaAsh;UniversityofFlorida/DepartmentofChemistry:Gainesville,FL,2019Calculations 6)Titration of KHP with NaOHMolesofKHPinsolution:Moles(mol)= Grams KHP ×1 mol KHP204.22 g1. 0.0946g0.00046mol2. 0.1071g0.00052mol3. 0.1068g0.00052molMolarityofNaOH:M of NaOH =1mol NaOH1 mol KHP×11 L of NaOH added1.9.40mLadded0.049M2.10.455mLadded0.050M3.9.70mLadded0.054MAverageMofNaOH:M 1+M 2+M 33=0.051MNaOHSDofNaOH:s=√Σ(x− x)2n=0.003RSDofNaOH:sx=CV=0.05Titration of HCl with 0.051 M NaOHMoles of NaOH0.051molL× L of NaOH added Trial 1:9.4mLNaOHadded0.00048molNaOHTrial 2:10.455mLNaOHadded0.00053molNaOHTrial 3:9.70mLNaOHadded0.00049molNaOH Molarity of HCLMofHCl=XmolNaOHx1 mol HCl1mol NaoH×10.005 L HCl stock soln1)0.00048molNaOH0.096MHCl2)0.00053molNaOH0.11MHCl3)0.00049molNaOH0.099MHClAverage=0.10MHClStandardDeviation=0.0007Relativestandarddeviation=0.007SodaAshcalculations(Sample38):% weight=g of soluteg of samplex1001) 0.0733gofsodaash:0.00475 L of HCl ×0.1 mol HCl1 L of HCl×1 mol of Na2C O32 mol of HCl×106 g1 mol Na2C O3=0.025 g of Na2C O3¿%w/w=34.35%(w/w)2) 0.0875gofsodaash:0.00503 L of HCl ×0.1 mol HCl1 L of HCl×1 mol of Na2C O32 molof HCl×106 g1 mol Na2C O3=0.027 g of Na2C O3¿%w/w=30.47%(w/w)3) 0.0756gofsodaash:0.005005 L of HCl ×0.1 mol HCl1 L of HCl×1 mol of Na2C O32 mol of HCl×106 g1 mol Na2C O3=0.027 g of Na2C O3¿%w/w=35.09%(w/w)Average% by weight =% 1+% 2+% 33= 33.30 %(ww)s=√(x−x)2n= 2RSD∨CV =sx=0.07Questions:1. Therequiredpropertiesofaprimarystandardsolidarethattheyhavehighpurity,areasonablecost,thermalstability,chemicalstability,knownchemistry,andahighequivalenceweight.NaOHisnotaprimarystandardbecauseitishygroscopic,meaningthatitattractsmoisturefromtheair,sotheconcentrationvariesovertime,suggestingthattheactualconcentrationofNaOHwillbelowerthantheanticipatedtheoreticalconcentration.2.