Qhov sib txawv tseem ceeb ntawm enthalpy ntawm atomisation thiab daim ntawv cog lus dissociation yog tias enthalpy ntawm atomisation piav txog lub zog xav tau los cais cov molecule rau hauv nws cov atoms whereas lub enthalpy ntawm daim ntawv cog lus dissociation piav qhia txog kev sib cais ntawm cov tshuaj bonds hauv ib lub molecule.
Qee lub sij hawm, enthalpy ntawm atomisation thiab enthalpy ntawm daim ntawv cog lus dissociation yog tib yam rau qee qhov sib txuas yooj yim yog tias muaj cov ntawv cog lus yooj yim. Qhov no yog vim hais tias, nyob rau hauv yooj yim compounds, dissociation ntawm bonds tsim cov atoms los ntawm cov molecule yog ua los ntawm.
Enthalpy of Atomisation yog dab tsi?
Enthalpy ntawm atomisation yog qhov hloov pauv hauv enthalpy uas tshwm sim thaum sib cais cov tshuaj lom neeg rau hauv nws cov atoms. Cov tshuaj no tuaj yeem yog cov khoom siv tshuaj lom neeg lossis tshuaj lom neeg. Peb tuaj yeem pom qhov hloov pauv enthalpy no li ΔHat Thaum lub sij hawm txheej txheem ntawm atomisation, txhua hom tshuaj tiv thaiv tau tawg, thiab tsis muaj qhov tsim. Yog li ntawd, enthalpy ntawm atomisation yeej ib txwm muaj txiaj ntsig zoo. Tus qauv enthalpy tus nqi rau qhov hloov enthalpy no yog "tus qauv enthalpy ntawm atomisation". Cov txheej txheem kev xav hauv cov ntsiab lus no yog 268.15 K kub thiab 1 bar siab.
Piv txwv li, enthalpy ntawm atomisation rau dej molecule yog hais txog lub zog yuav tsum tau cais ob hydrogen atoms thiab cov pa atom hauv dej molecule. Nyob rau hauv lwm yam lus, lub enthalpy ntawm atomisation rau dej yog cov sum ntawm cov nyiaj dissociation energies ntawm ob O-H bonds. Ib yam li ntawd, lub enthalpy ntawm atomisation rau ib qho khoom siv yog qhov enthalpy ntawm sublimation rau cov khoom ntawd vim tias sublimation cuam tshuam rau kev hloov pauv ntawm cov khoom mus rau hauv cov pa roj monoatomic thaum evaporation.
Enthalpy of Bond Dissociation yog dab tsi?
Enthalpy ntawm daim ntawv cog lus dissociation piav qhia txog kev hloov pauv enthalpy uas tshwm sim thaum lub sijhawm sib cais ntawm cov tshuaj lom neeg. Hauv lwm lo lus, nws yog qhov ntsuas ntawm lub zog ntawm cov khoom siv tshuaj lom neeg. Yog li ntawd, peb tuaj yeem hais tias tus qauv enthalpy hloov pauv uas tshwm sim thaum cov tshuaj lom neeg daim ntawv cog lus A-B tawg los ntawm hemolysis thiab fragments A thiab B yog enthalpy ntawm daim ntawv cog lus dissociation. Yog hais tias lub molecule peb tab tom txiav txim siab yog diatomic molecule, ces daim ntawv cog lus dissociation enthalpy yog sib npaug rau enthalpy ntawm atomisation. Feem ntau, A thiab B tawg tau muab los ntawm qhov kev sib koom ua ke no yog hom radical. Peb tuaj yeem pom qhov enthalpy ntawm daim ntawv cog lus dissociation li DH0
Muaj ntau txoj hauv kev uas peb tuaj yeem siv los ntsuas qhov sib txawv ntawm daim ntawv cog lus xws li kev txiav txim siab spectrometric ntawm qib zog, tsim cov radicals los ntawm pyrolysis lossis photolysis, ntsuas cov tshuaj kinetics thiab sib npaug, ntau yam calorimetric thiab electrochemical txoj kev, thiab lwm yam.
Qhov txawv ntawm Enthalpy ntawm Atomisation thiab Bond Dissociation yog dab tsi?
Qhov sib txawv tseem ceeb ntawm enthalpy ntawm atomisation thiab daim ntawv cog lus dissociation yog tias enthalpy ntawm atomisation piav txog lub zog yuav tsum tau cais cov molecule rau hauv nws cov atoms whereas lub enthalpy ntawm daim ntawv cog lus dissociation piav qhia txog kev sib cais ntawm cov tshuaj bonds hauv ib lub molecule. Daim ntawv cog lus dissociation enthalpy thiab enthalpy ntawm atomisation yeej ib txwm muaj txiaj ntsig zoo. Qee lub sij hawm, enthalpy ntawm atomisation thiab enthalpy ntawm daim ntawv cog lus dissociation yog tib yam rau qee qhov sib txuas yooj yim yog tias muaj cov ntawv cog lus yooj yim. Txawm li cas los xij, cov ntsiab lus no txawv ntawm txhua lub sijhawm.
Hauv qab cov lus infographic ntau qhov sib txawv ntawm enthalpy ntawm atomisation thiab daim ntawv cog lus dissociation.
Summary – Enthalpy of Atomisation vs Bond Dissociation
Enthalpy ntawm atomisation thiab daim ntawv cog lus dissociation tuaj yeem siv sib hloov rau qee qhov sib txuas yooj yim, tab sis tsis yog ib txwm lawv sib npaug. Qhov sib txawv tseem ceeb ntawm enthalpy ntawm atomisation thiab daim ntawv cog lus dissociation yog tias enthalpy ntawm atomisation piav qhia lub zog yuav tsum tau cais cov molecule rau hauv nws cov atoms whereas lub enthalpy ntawm daim ntawv cog lus dissociation piav txog qhov dissociation ntawm tshuaj bonds nyob rau hauv ib molecule.
