Tsis siv neeg acid-base titration nrog qhov kawg taw tes qhia los ntawm pH meter
(1) Lub hom phiaj ntawm kev sim
(1) Nkag siab txog kev ua haujlwm thiab kev siv pH meter. (2) Muaj peev xwm siv pH ntsuas rau acid-base titration.
(2) Kev sim txoj cai
Potentiometric titration yog ib txoj kev tshuaj ntsuam uas siv qhov dhia hauv electrode peev xwm los txiav txim qhov kawg. Nyob rau hauv cov txheej txheem titration, nrog rau qhov sib ntxiv ntawm titrant, vim muaj tshuaj lom neeg cov tshuaj tiv thaiv nyob rau hauv lub system, lub concentration ntawm ion yuav tsum tau ntsuas yog tas li hloov, thiab lub peev xwm ntawm electrode ntawm qhov taw qhia electrode kuj hloov tsis tu ncua. Nyob ze ntawm stoichiometric taw tes, qhov concentration ntawm ion yuav tsum tau ntsuas dheev hloov Dhia, lub peev xwm electrode ntawm qhov taw qhia electrode kuj dhia, thiaj li txiav txim siab qhov kawg taw tes titration. Txawm li cas los xij, nws yog cumbersome los txiav txim qhov kawg taw tes los ntawm kev siv thawj qhov kev txiav txim derivative titration nkhaus ntawm ΔE / ΔV tiv thaiv V los yog qhov thib ob-order derivative titration nkhaus ntawm △E2 / △V2 piv V. Yog li ntawd, qhov kawg taw tes feem ntau yog txiav txim siab. los ntawm tsis siv neeg potentiometric titration.
Tsis siv neeg potentiometric titration yog kom tau txais qhov kawg peev xwm ntawm titration system los ntawm kev suav cov txheej txheem lossis phau ntawv titration raws li cov kev paub, tom qab ntawd kho qhov kawg ntawm qhov tsis siv neeg potentiometric titrator mus rau qhov yuav tsum tau muaj peev xwm, cia nws txiav titrate, thaum kawg taw tes yog mus txog, lub titration yog cia li muab tua ntaus ntawv thiab qhia cov titrated ntim.
Hauv qhov kev sim no, 0.1mol/L HCL tov yog siv los titrate NaOH cov tshuaj uas tsis paub concentration, thiab pH composite electrode yog siv los ua tus taw qhia electrode, yog li qhov taw qhia electrode tuaj yeem hloov pauv ntawm hydrogen ion concentration. (los yog kev hloov ntawm electrode muaj peev xwm) nyob rau hauv lub titration system mus rau hauv kev hloov ntawm pH los qhia qhov kawg point. Thaum pH sib npaug rau 7, lub tshuab tsis siv neeg titrator nres titration thiab qhia txog qhov ntim ntawm titrant siv. (Piv txwv: Txij li thaum lub titration tau ua tiav los ntawm lub titrator, titration ceev kuj qeeb thiab siv sij hawm ntev. Yog li ntawd, peb siv phau ntawv titration thaum lub sij hawm sim los tswj cov txheej txheem kev sim thiab txhim kho qhov kev ua tau zoo ntawm qhov kev sim.)
(3) Kev sim ntsuas thiab cov tshuaj reagents
ZD{{0}}} hom tsis siv neeg potentiometric titrator, 0.1mol/L HCL tov, NaOH tov ntawm tsis paub concentration, 20ml pipette pob ntseg ntxuav pob, hlau nplaum, 2 150ml beakers, 1 500ml beaker, lim ntawv, thiab lwm yam.
(4) Kev sim cov kauj ruam
(1) Qhib lub hwj chim, pib lub tshuab hluav taws xob tsis siv neeg lub tshuab hluav taws xob, thiab preheat rau 5 feeb.
(2) Kev ntxuav thiab yaug ntawm lub tshuab tsis siv neeg potentiometric titrator: ntxig lub catheter rau hauv lub raj mis uas muaj dej distilled, nias lub pob tu, thiab pib ntxuav raws li lub sijhawm tu lub sijhawm (3 zaug); tom qab ntawd ntxig lub catheter rau hauv lub raj mis uas muaj 0.1mol/ Hauv HCL tov L, nias lub pob ntxuav kom yaug ib zaug; Yaug lub iav qhov muag teev ntawm pH composite electrode thiab lub tog raj kheej ntawm qhov ntsuas kub sensor nrog dej distilled thiab qhuav lawv nrog lim ntawv. (3) Pipette 20 mL ntawm NaOH tov ntawm cov tsis paub concentration rau hauv lub beaker huv si, ntxiv ib tug hlau nplaum, muab tso rau ntawm lub electromagnetic stirring qhov chaw ntawm lub automatic potentiometric titrator, ntxiv txaus distilled dej rau raus lub khob pob ntawm lub pH composite electrode nyob rau hauv cov tshuaj. (4) Nias tus yuam sij nplawm, thiab teem lub nplawm ceev rau 50. Nias tus yuam sij titration kom nkag mus rau qhov kev xaiv hom titration, xaiv phau ntawv titration, thiab nias lub khawm kom paub meej; txoj kab nqes thiab lub peev xwm yog defaulted los ntawm lub kaw lus, nias tus yuam sij lees paub; xaiv lub ntim ntim ua ntej thiab lub ntim ntim tom ntej thiab teeb tsa (tus nqi tshwj xeeb nyob ntawm qhov xwm txheej tiag), Nias tus yuam sij nkag los pib titration. Tom qab lub ntim ntim ua ntej ntxiv, nias lub pob Ntxiv ntxiv. Thaum pH ze rau 7, qhov ntim ntxiv yuav tsum tau teem kom tsawg li tsawg tau. Thaum kawg pH nyob rau hauv thaj tsam ntawm 7. Rov ua cov haujlwm saum toj no peb zaug.
(5) Yaug lub raj xa dej ntawm lub tshuab tsis siv neeg titrator nrog dej distilled peb zaug, thiab tom qab ntawd tua lub ntsuas. Yaug cov pH sib xyaw electrode thiab so kom qhuav nrog cov ntawv lim, ntxiv cov tshuaj KCL saturated rau hauv pH composite electrode cover, thiab ntxig pH composite electrode rau hauv lub hau.
(5) Kev ceev faj
Lub ntsiab sensing ib feem ntawm lub composite electrode yog lub teeb ntawm lub electrode. Lub teeb yog nyias nyias thiab yuav tsum tsis txhob kov cov khoom tawv. Tom qab kev ntsuas, muab tso rau ntawm lub hau tiv thaiv, thiab muab me me ntawm cov tshuaj ntxiv (3mol / L potassium chloride tov) rau hauv lub hau kom cov roj electrode moist.
Cov ntsiab lus: Qhov concentration ntawm sodium hydroxide ntsuas hauv qhov kev sim yog {{0}}.092 mol / L, thiab tus qauv sib txawv yog 0.2 feem pua. Qhov yuam kev yog me ntsis loj, uas tej zaum yuav yog vim qhov kev txiav txim tsis raug ntawm qhov kawg ntawm titration, thiab qhov titration tau nres ua ntej cov hydrochloric acid ntxiv tau tshwm sim.
