Qhov sib txawv tseem ceeb ntawm kev sib cais thiab kaw qhov system yog tias cov kab ke sib cais tsis tuaj yeem pauv cov teeb meem thiab lub zog nrog ib puag ncig tab sis, txawm tias lub kaw lus kaw dhau los tsis tuaj yeem pauv qhov teeb meem nrog ib puag ncig, nws tuaj yeem pauv lub zog.
Rau qhov yooj yim ntawm kev kawm chemistry, peb faib lub ntiaj teb ua ob ntu. Ib feem peb yuav kawm yog "system", thiab tus so yog "ib puag ncig". Piv txwv li, ib lub cev tej zaum yuav yog cov kab mob, cov tshuaj tiv thaiv kab mob lossis txawm tias ib lub cell. Muaj ib tug ciam teb ntawm ib tug system thiab ib puag ncig. Tus ciam teb txhais tau tias lub Scope ntawm lub system. Qee zaum, qhov teeb meem thiab lub zog sib pauv los ntawm cov ciam teb no. Tsis tas li ntawd, peb tuaj yeem faib cov txheej txheem ua ob pawg; lawv yog cov qhib system thiab kaw kaw. Ib qho kev sib cais yog ib daim ntawv ntawm lub kaw lus kaw.
Dab tsi yog Isolated System?
Ib qho kev sib cais yog ib daim ntawv ntawm lub kaw lus kaw. Tab sis, nws txawv ntawm lub kaw lus kaw vim nws tsis muaj kev sib cuag nrog cov neeg kho tshuab lossis thermal nrog nws nyob ib puag ncig. Qhov ntawd txhais tau tias; cov txheej txheem cais tsis tuaj yeem pauv cov teeb meem thiab lub zog nrog ib puag ncig. Tsis tas li ntawd, cov tshuab no ncav cuag qhov sib npaug ntawm lub sijhawm, los ntawm kev ntsuas qhov siab, qhov kub thiab txias, lossis lwm yam tsis muaj.
Xyaum, ib qho kev sib cais tsis muaj nyob vim tias txhua yam muaj kev cuam tshuam nrog ib leeg hauv qee txoj hauv kev. Txawm li cas los xij, peb tuaj yeem txiav txim siab tag nrho lub qab ntuj khwb yog ib qho kev sib cais, xav tias tsis muaj kev hloov ntawm cov teeb meem thiab lub zog tawm sab nraud. Raws li txoj cai, qhov no yog qhov tseem ceeb thaum tsim cov qauv. Piv txwv li, thawj thiab thib ob txoj cai thermodynamic qhia txog ib qho kev sib cais.
Daim duab 01: Kev sib piv ntawm Isolated Systems nrog qhib thiab kaw Systems
Thawj txoj cai ntawm thermodynamics hais tias "lub zog sab hauv ntawm ib qho kev sib cais yog tas li." Txoj cai thib ob ntawm thermodynamics hais tias "qhov entropy ntawm ib qho kev sib cais nce ntxiv nyob rau hauv cov txheej txheem ntawm tus kheej." Txawm li cas los xij, txoj cai no tsuas muaj tseeb rau cov kab ke sib cais xwb. Lub entropy yuav nce ntxiv nyob rau lub sijhawm nyob rau hauv ib qho kev sib cais thiab yuav ncav cuag tus nqi siab tshaj plaws ntawm qhov sib npaug. Hauv luv luv, tag nrho lub zog ntawm cov tshuab no tsis tuaj yeem nce ntxiv. Yog li, qhov entropy tsis tuaj yeem txo qis.
Caw System yog dab tsi?
Hauv lub kaw lus kaw, qhov teeb meem tsis tuaj yeem hla ciam teb. Yog li ntawd, qhov teeb meem hauv lub kaw lus kaw yog ib txwm zoo ib yam. Txawm li cas los xij, nyob rau hauv hom kab ke no, lub zog sib pauv nrog ib puag ncig. Piv txwv li, thaum muaj qhov tshwm sim tshwm sim, lub kaw lus tuaj yeem nthuav dav, lossis nws tuaj yeem hloov lub zog mus rau ib puag ncig yog tias nws nyob ntawm qhov kub qis dua.
Daim duab 02: Ib Qhov Txheej Txheem thiab nws ib puag ncig sib cais los ntawm Ciam Teb
Ex: Yog tias peb npog sab saum toj ntawm lub khob dej tshuaj yej nrog lub hau, ces nws dhau los ua qhov kaw. Nyob ntawd, cov chav tsis tuaj yeem khiav ntawm qhov system. Tsis tas li ntawd, cov roj molecules nyob ib puag ncig tsis tuaj yeem nkag mus rau hauv lub cev. Yog li ntawd, tsis muaj kev sib pauv ntawm qhov teeb meem. Txawm li cas los xij, qhov kub ntawm cov tshuaj yej pauv nrog ib puag ncig. Peb tuaj yeem hnov cua sov yog tias peb kov lub hau ntawm lub khob. Yog li ntawd lub zog tawm sab nraud li thermal zog. Nyob ntawd, lub kaw lus tau txais qhov sib npaug nrog ib puag ncig thaum qhov kub thiab txias sab hauv thiab sab nraud ntawm qhov system ua sib npaug.
Qhov txawv ntawm Isolated System thiab Kaw System yog dab tsi?
Ib thaj tsam cais ib qho system thiab nws ib puag ncig. Peb tuaj yeem muab lub npe hu ua qhov qhib lossis kaw qhov system nyob ntawm kev sib pauv ntawm cov teeb meem thiab lub zog los ntawm tus ciam teb no. Ib qho kev sib cais kuj yog ib hom kev kaw kaw. Qhov sib txawv tseem ceeb ntawm kev sib cais thiab kaw qhov system yog tias cov kab ke sib cais tsis tuaj yeem pauv cov teeb meem thiab lub zog nrog ib puag ncig tab sis, txawm tias lub kaw lus kaw tsis tuaj yeem pauv qhov teeb meem nrog ib puag ncig, nws tuaj yeem pauv lub zog.
Raws li lwm qhov sib txawv tseem ceeb ntawm kev sib cais thiab kaw qhov system, peb tuaj yeem hais tias entropy ntawm ib qho kev sib cais tsis tuaj yeem txo qis thaum entropy ntawm lub kaw lus kaw tuaj yeem txo qis. Ntxiv mus, cov tshuab cais tawm yog theoretical; uas txhais tau tias, cov tshuab no tsis muaj nyob hauv qhov tseeb. Txawm li cas los xij, kaw tshuab muaj nyob hauv qhov tseeb.
Summary – Isolated System vs Kaw System
System muaj ob hom; lawv yog cov qhib system thiab kaw kaw. Isolated systems kuj yog ib hom kaw kaw. Txawm li cas los xij, muaj qee qhov sib txawv ntawm lawv. Qhov sib txawv tseem ceeb ntawm kev sib cais thiab kaw qhov system yog tias cov kab ke sib cais tsis tuaj yeem pauv cov teeb meem thiab lub zog nrog ib puag ncig tab sis, txawm tias lub kaw lus kaw dhau los tsis tuaj yeem pauv qhov teeb meem nrog ib puag ncig, nws tuaj yeem pauv lub zog.
