Qhov sib txawv tseem ceeb ntawm electrode muaj peev xwm thiab lub peev xwm ntawm tes yog qhov muaj peev xwm electrode yog hais txog lub peev xwm ntawm ib qho hluav taws xob hauv lub xov tooj kom tau txais kev txo qis lossis oxidized thaum lub peev xwm ntawm tes yog qhov sib txawv ntawm cov electrode muaj peev xwm ntawm cov electrodes tam sim no hauv electrochemical. cell.
Electrode muaj peev xwm thiab lub peev xwm ntawm tes yog cov ntsiab lus uas piav qhia lub zog hluav taws xob ntawm lub xov tooj hluav taws xob. Electrode muaj peev xwm muab lub peev xwm voltaic ntawm ib qho electrode thaum lub peev xwm ntawm tes txiav txim siab txog qhov muaj peev xwm ntawm ob lub electrodes.
Electrode Potential yog dab tsi?
Electrode muaj peev xwm yog qhov nyiam ntawm cov khoom siv hluav taws xob hauv cov hluav taws xob hluav taws xob kom txo qis lossis oxidized. Nws yog lub zog electromotive ntawm ib lub cell. Muaj peb yam cuam tshuam rau tus nqi ntawm lub peev xwm electrode: xwm ntawm electrode, qhov concentration ntawm ions hauv cov tshuaj electrolytic thiab kub. Rau ib qho hluav taws xob hluav taws xob, tag nrho cov peev xwm yog qhov sib npaug ntawm cov khoom siv hluav taws xob ntawm ob lub electrodes. Peb tuaj yeem txheeb xyuas qhov muaj peev xwm electrode li E. Txawm li cas los xij, peb tsis tuaj yeem ntsuas qhov muaj peev xwm electrode hauv kev sib cais. Nws yuav tsum tau ntsuas nyob rau hauv cov tshuaj tiv thaiv nrog rau lwm yam electrode.
Daim duab 01: Ib qho yooj yim Electrochemical Cell
Ntxiv mus, lub peev xwm electrode nyob ntawm qhov ntau ntawm cov electrodes, qhov kub thiab txias ntawm electrochemical cell, thiab lub siab (yog tias lub cell muaj roj electrodes). Feem ntau, cov peev txheej electrode raug ntsuas raws li tus qauv electrode.
Tus qauv txheem electrode yog hydrogen electrode thiab nws cov electrode muaj peev xwm raug coj los ua xoom. Tsis tas li ntawd, peb yuav tsum siv cov txheej txheem thermodynamic hauv kev txiav txim thaum ntsuas qhov muaj peev xwm; txwv tsis pub, peb tsis tuaj yeem tau txais tus nqi tiag tiag vim tias qhov muaj peev xwm electrode nyob ntawm qhov kub thiab txias, siab, thiab lwm yam. Ntawm no, cov qauv ntsuas kub muaj xws li ntsuas tawm tsam hydrogen electrode, cov tshuaj electrolytic muaj qhov concentration ntawm 1 mol / L, siab ntawm 1. atm, thiab kub ntawm 25 ° C.
Cell Potential yog dab tsi?
Cell peev xwm yog hais txog tag nrho cov peev xwm ntawm cov hluav taws xob hluav taws xob uas muaj ob lub electrodes. Ntawm no, cov hluav taws xob hluav taws xob yuav tsum muaj ob qhov kev sib cais ib nrab uas tshwm sim thaum uas tig mus rau ib leeg thiab tom qab ntawd, lub peev xwm ntawm tes yog raws li hauv qab no:
Ecell=oxidation muaj peev xwm + txo qhov peev xwm
Yog li ntawd, lub peev xwm ntawm tes yog qhov suav ntawm cathode electrode muaj peev xwm thiab lub peev xwm anode electrode. Lub cell voltaic tiag tiag txawv ntawm cov txheej txheem. Yog li ntawd, peb yuav tsum tau kho qhov kev sim ntsuas kom tau txais tus qauv tus nqi. Nws yog raws li nram no:
Ecell =E0cell – (RT/nF)lnQ
Qhov twg Ecell yog qhov kev sim ntawm tes, E0cell yog tus qauv cell peev xwm, R yog universal tas li, T yog qhov kub thiab txias, n yog moles ntawm electrons pauv nyob rau hauv ib nrab-reactions, F yog Faraday tas li thiab Q yog cov tshuaj tiv thaiv thermodynamic quotient.
Qhov txawv ntawm Electrode Potential thiab Cell Potential yog dab tsi?
Qhov sib txawv tseem ceeb ntawm electrode muaj peev xwm thiab lub peev xwm ntawm tes yog qhov muaj peev xwm electrode yog hais txog lub peev xwm ntawm ib qho hluav taws xob hauv lub xov tooj kom tau txais kev txo qis lossis oxidized thaum lub peev xwm ntawm tes yog qhov sib txawv ntawm cov electrode muaj peev xwm ntawm cov electrodes tam sim no hauv electrochemical. cell. Yog li, electrode muaj peev xwm muab lub peev xwm voltaic ntawm ib qho electrode thaum lub peev xwm ntawm tes txiav txim siab ob qho tib si electrodes.
Ntxiv mus, lwm qhov sib txawv tseem ceeb ntawm cov peev txheej electrode thiab lub peev xwm ntawm tes yog qhov tsis tuaj yeem ntsuas cov peev txheej electrode vim tias nws yog tus nqi txheeb ze, tab sis lub peev xwm ntawm tes tuaj yeem ntsuas tau yooj yim vim peb yuav tsum nrhiav qhov sib txawv ntawm qhov muaj peev xwm electrode., uas yog txheeb ze tus nqi.
Summary – Electrode Potential vs Cell Potential
Electrode muaj peev xwm thiab lub peev xwm ntawm tes tau tham hauv electrochemistry, hais txog electrochemical hlwb. Qhov sib txawv tseem ceeb ntawm electrode muaj peev xwm thiab lub peev xwm ntawm tes yog qhov muaj peev xwm electrode yog hais txog lub peev xwm ntawm cov khoom siv hluav taws xob hauv lub xov tooj ntawm tes kom txo qis lossis oxidized whereas cell muaj peev xwm yog qhov sib txawv ntawm cov electrode muaj peev xwm ntawm cov electrodes tam sim no nyob rau hauv ib qho electrochemical cell.
