Qhov sib txawv tseem ceeb ntawm theem pib thiab tus nqi txiav txim siab yog cov theem pib yog cov tshuaj lom neeg cov tshuaj tiv thaiv uas cov reactants hnov qab muab cov khoom kawg lossis ib qho nruab nrab thaum tus nqi txiav txim siab yog qib qis tshaj ntawm cov txheej txheem ntau.
Cov ntsiab lus theem pib thiab tus nqi txiav txim siab yog siv los tham txog cov tshuaj tiv thaiv cov tshuaj tiv thaiv, tshwj xeeb tshaj yog thaum muaj ob lossis ntau kauj ruam ua ntej tsim cov khoom kawg. Txhua kauj ruam ntawm cov txheej txheem multistep no hu ua theem pib. Cov kauj ruam no muaj tus nqi sib txawv. Tus nqi txiav txim cov kauj ruam ntawm cov txheej txheem muaj tus nqi qeeb tshaj plaws.
Ib kauj ruam yog dab tsi?
Cov kauj ruam theem pib yog ib kauj ruam uas muaj nyob rau hauv ntau txoj kev. Ib theem pib yog cov tshuaj tiv thaiv tshuaj uas ib los yog ob lub reactants hnov qab muab cov khoom kawg lossis cov khoom nruab nrab. Nws yog ib kauj ruam kev tawm tsam, thiab nws muaj ib qho kev hloov pauv. Feem ntau, yog tias tsis muaj cov khoom nruab nrab uas tsim tawm thaum lub sij hawm muaj tshuaj lom neeg, cov tshuaj tiv thaiv no yog hu ua cov tshuaj tiv thaiv theem pib. Ntxiv mus, ib tug mechanism rau ib tug tshuaj tiv thaiv yog ib tug sau ntawm theem pib. Yog li ntawd, cov tshuaj tiv thaiv theem pib piav qhia txog tib lub sijhawm thaum lub sijhawm cov tshuaj tiv thaiv uas cov molecules tawg thiab / lossis tsim cov ntawv cog lus tshiab.
Cov lej ntawm tag nrho cov theem pib sib npaug ua rau tag nrho cov tshuaj tiv thaiv. Cov theem pib ntawm cov txheej txheem multistep muaj cov tshuaj tiv thaiv sib txawv; e.g. qee cov theem pib tshwm sim sai thaum lwm cov kauj ruam qeeb heev. Yog li ntawd, tus nqi txiav txim siab txog qib lossis qib qis tshaj ntawm cov tshuaj tiv thaiv kuj yog hom tshuaj tiv thaiv theem pib.
Cov tshuaj tiv thaiv theem pib tuaj yeem raug cais raws li lawv cov molecularity. Ntawm no, tus naj npawb ntawm cov molecules koom nrog hauv cov tshuaj tiv thaiv yog siv los muab cov molecularity ntawm theem pib. E.g. Yog hais tias muaj ib tug reactant, nws yog unimolecular, thiab yog hais tias muaj ob reactants, nws yog bimolecular. Unimolecular thiab bimolecular yog cov feem ntau ntawm cov tshuaj tiv thaiv theem pib. Termolecular (peb reactants) cov tshuaj tiv thaiv tsis tshua muaj vim tias kev sib tsoo ntawm peb lub molecules tib lub sijhawm tsis tshua muaj.
Tus nqi txiav txim siab yog dab tsi?
Tus nqi txiav txim siab yog kauj ruam qeeb tshaj plaws ntawm cov txheej txheem tshuaj tiv thaiv ntau. Nws yog ib kauj ruam ntawm cov kauj ruam. Txawm li cas los xij, qee qhov kev cuam tshuam tsuas muaj ib qho tshuaj tiv thaiv (tsis yog cov tshuaj tiv thaiv kab mob); Yog li, cov tshuaj tiv thaiv no ib txwm yog tus nqi txiav txim siab cov tshuaj tiv thaiv. Cov tshuaj tiv thaiv uas muaj tus nqi qeeb tshaj plaws yog coj los ua tus nqi txiav txim siab vim nws txwv tus nqi ntawm cov tshuaj tiv thaiv.
Daim duab 01: Ob-headed Arrows qhia tus nqi Txiav Txim Kauj Ruam ntawm txhua qhov kev tawm tsam
Ib qho piv txwv hauv qab no.
NO2 + NO2 → TSIS + NO3 (qib kauj ruam, ntsuas ntsuas)
NO3 + CO → NO2 + CO2 (fast step)
Qhov txawv ntawm Qib Qeb thiab Tus Nqi Txiav Txim Them Li Cas?
Qhov sib txawv tseem ceeb ntawm theem pib thiab tus nqi txiav txim siab yog cov kauj ruam theem pib yog cov tshuaj lom neeg cov tshuaj tiv thaiv uas cov reactants hnov qab muab cov khoom kawg lossis ib qho nruab nrab thaum tus nqi txiav txim siab yog qib qis tshaj ntawm cov txheej txheem ntau. Yog li ntawd, cov kauj ruam theem pib tuaj yeem ua tau sai lossis qeeb, thaum tus nqi txiav txim siab theem ib txwm yog qhov qeeb tshaj plaws.
Hauv qab infographic qhia txog qhov sib txawv ntawm theem pib thiab tus nqi txiav txim siab kauj ruam.
Summary – Qeb Qeb vs Rate Determining Step
Cov ntsiab lus theem pib thiab tus nqi txiav txim siab yog siv los tham txog cov tshuaj tiv thaiv cov tshuaj tiv thaiv thaum muaj ob lossis ntau cov kauj ruam tshwm sim ua ntej tsim cov khoom kawg. Qhov sib txawv tseem ceeb ntawm theem pib thiab tus nqi txiav txim cov kauj ruam yog theem pib yog cov tshuaj lom neeg cov tshuaj tiv thaiv uas cov reactants hnov mob los muab cov khoom kawg lossis ib qho nruab nrab thaum tus nqi txiav txim siab yog qib qis tshaj ntawm cov txheej txheem multistep.
