Qhov sib txawv tseem ceeb ntawm qhov tshwm sim tsis raws cai thiab tsis muaj qhov tshwm sim yog qhov tshwm sim ntawm tus kheej muaj qhov tsis zoo Gibbs dawb lub zog thaum qhov tsis muaj qhov tshwm sim muaj lub zog zoo Gibbs dawb.
Cov tshuaj tiv thaiv tuaj yeem yog tshuaj lom neeg lossis tshuaj lom neeg. Peb tuaj yeem faib cov kev cuam tshuam no rau hauv ob pawg raws li qhov tshwm sim tshwm sim thiab tsis muaj qhov tshwm sim. Ib qho kev tshwm sim tshwm sim tsis muaj kev cuam tshuam sab nraud. Tab sis cov kev tshwm sim uas tsis yog tshwm sim tsis tuaj yeem ua tiav yam tsis muaj kev cuam tshuam sab nraud. Cia peb tham txog cov ntsiab lus ntxiv ntawm cov kev tshwm sim no thiab tabulate qhov sib txawv ntawm qhov tshwm sim ntawm tus kheej thiab tsis ua raws li kev xav.
Yuav ua li cas tshwm sim?
Kev tshwm sim tshwm sim yog tshuaj lom neeg lossis tshuaj lom neeg uas tshwm sim yam tsis muaj kev cuam tshuam ntawm lwm yam. Tsis tas li ntawd, cov tshuaj tiv thaiv no nyiam ua kom cov entropy thaum txo qis enthalpy ntawm lub tshuab thermodynamic. Txij li cov tshuaj tiv thaiv no tsis xav tau lwm yam, lawv tshwm sim ib txwm muaj. Yog li cov tshuaj tiv thaiv no nyiam tsim cov khoom lag luam nyob rau hauv cov xwm txheej uas cov tshuaj tiv thaiv tshwm sim. Gibbs lub zog pub dawb ntawm qhov tshwm sim tshwm sim yog qhov tsis zoo.
Feem ntau ntawm cov kev tshwm sim tshwm sim sai sai vim tias nws nyiam tsim cov khoom ntau dua li khaws cov reactant raws li nws yog. Piv txwv li: combustion ntawm hydrogen. Tab sis qee qhov kev tshwm sim tshwm sim qeeb heev. Piv txwv li: Hloov graphite rau hauv pob zeb diamond. Tsis tas li ntawd, nyob rau hauv ib co reversible cov lus teb, ib qho kev taw qhia cov tshuaj tiv thaiv yog nyiam dua lwm cov kev taw qhia. Piv txwv li, hauv kev tsim cov pa roj carbon dioxide thiab dej los ntawm carbonic acid, cov tshuaj tiv thaiv rau pem hauv ntej yog favoured; tsim ntawm carbon dioxide thiab dej yog spontaneous.
H2CO3 ↔ CO2 + H2 O
Dab tsi yog Kev Tsis Txaus Siab?
Cov tshuaj tiv thaiv tsis raws cai yog tshuaj lom neeg lossis tshuaj lom neeg uas tuaj yeem tshwm sim yam tsis muaj kev cuam tshuam ntawm lwm yam. Yog li ntawd, cov tshuaj tiv thaiv no tsis ua raws li tej yam ntuj tso.
Daim duab 01: Kev Sib Piv Ntawm Kev Ua Phem Tsis Txaus Siab thiab Tsis Ua Raws Cai
Yog li, peb yuav tsum muab qee yam sab nraud rau cov kev cuam tshuam no kom nce qib. Piv txwv li: peb tuaj yeem muab cua sov, muab qee qhov siab, ntxiv cov catalyst, thiab lwm yam. Ntxiv mus, Gibbs dawb lub zog yog qhov zoo rau cov tshuaj tiv thaiv no.
Yuav luag tag nrho cov tshuaj tiv thaiv tsis raws cai yog endothermic; lawv tso lub zog rau sab nraud. Cov tshuaj tiv thaiv no nrog rau kev txo qis hauv entropy. Piv txwv li: tsim cov nitrogen monoxide (tsis muaj roj) los ntawm cov tshuaj tiv thaiv ntawm oxygen thiab nitrogen nyob rau hauv peb cov huab cua yog nonspontaneous ntawm ib txwm kub thiab siab tej yam kev mob. Txawm li cas los xij, qhov tshuaj tiv thaiv no tshwm sim ntawm qhov kub siab heev.
Dab tsi yog qhov txawv ntawm qhov tshwm sim tshwm sim thiab tsis tshwm sim?
Kev tshwm sim tshwm sim yog tshuaj lom neeg lossis tshuaj lom neeg uas tshwm sim yam tsis muaj kev cuam tshuam ntawm lwm yam. Lawv pom zoo kom nce lub entropy thaum txo qis enthalpy ntawm cov txheej txheem thermodynamic. Ntxiv mus, Gibbs dawb lub zog ntawm cov tshuaj tiv thaiv tus kheej yog qhov tsis zoo. Txawm li cas los xij, cov tshuaj tiv thaiv tsis raws cai yog tshuaj lom neeg lossis tshuaj lom neeg uas tuaj yeem tshwm sim yam tsis muaj kev cuam tshuam ntawm lwm yam. Lawv tsis pom zoo kom nce entropy lossis txo qis enthalpy ntawm cov xwm txheej ib txwm muaj. Tsis tas li ntawd, Gibbs dawb lub zog ntawm cov tshuaj tiv thaiv uas tsis yog tshwm sim yog qhov muaj txiaj ntsig zoo.
Summary – Spontaneous vs Nonspontaneous Reactions
Txhua qhov kev tshwm sim muaj ob hom kev tshwm sim xws li kev tshwm sim tshwm sim thiab tsis ua raws li qhov tshwm sim. Qhov sib txawv ntawm qhov tshwm sim ntawm qhov tshwm sim thiab tsis ua raws li qhov tshwm sim yog qhov tshwm sim ntawm tus kheej muaj qhov tsis zoo Gibbs lub zog tsis muaj zog thaum tsis muaj qhov tshwm sim muaj qhov zoo Gibbs dawb zog.
