Qhov Tseem Ceeb Qhov txawv - Kev daws Zog vs Lattice Zog
Kev daws lub zog yog qhov hloov pauv hauv Gibbs lub zog ntawm cov kuab tshuaj thaum lub kuab tshuaj yaj hauv cov kuab tshuaj ntawd. Lub zog lattice yog tus nqi ntawm lub zog tso tawm thaum lub sij hawm tsim ib lub lattice los ntawm ions los yog tus nqi ntawm lub zog yuav tsum tau ua kom puas lub lattice. Qhov sib txawv tseem ceeb ntawm kev daws lub zog thiab lub zog lattice yog tias kev daws lub zog muab qhov hloov pauv ntawm enthalpy thaum solute ib qho kuab tshuaj nyob rau hauv cov kuab tshuaj thaum lub zog lattice muab qhov kev hloov ntawm enthalpy thaum tsim (los yog tawg) ntawm lub lattice.
Kev daws lub zog yog dab tsi?
Kev daws lub zog yog qhov hloov pauv hauv Gibbs lub zog thaum lub ion lossis molecule raug xa mus los ntawm lub tshuab nqus tsev (los yog theem roj) mus rau qhov hnyav. Kev daws yog kev sib cuam tshuam ntawm cov kuab tshuaj thiab cov molecules lossis ions ntawm cov kuab tshuaj. Lub solute yog lub compound uas yuav yaj nyob rau hauv cov kuab tshuaj. Qee cov kuab tshuaj yog tsim los ntawm cov molecules thaum qee qhov muaj ions.
Kev sib cuam tshuam ntawm cov kuab tshuaj thiab cov kuab tshuaj txiav txim siab ntau yam ntawm cov kuab tshuaj. Piv txwv li: solubility, reactivity, xim, thiab lwm yam. Thaum lub sij hawm tus txheej txheem ntawm kev daws teeb meem, solute hais yog surrounded los ntawm hnyav molecules tsim kev daws complexes. Thaum cov kuab tshuaj koom nrog hauv qhov kev daws teeb meem no yog dej, cov txheej txheem hu ua hydration.
Ntau hom tshuaj tiv thaiv thiab kev sib cuam tshuam raug tsim thaum lub sijhawm daws teeb meem; Hydrogen bonds, ion-dipole kev sib cuam tshuam thiab Van der Waal rog. Cov khoom ntxiv ntawm cov kuab tshuaj thiab cov kuab tshuaj txiav txim siab qhov solubility ntawm cov kuab tshuaj hauv cov kuab tshuaj. Piv txwv li, polarity yog ib qho tseem ceeb uas txiav txim siab qhov solubility ntawm cov kuab tshuaj hauv cov kuab tshuaj. Polar solutes yaj zoo nyob rau hauv polar solvents. Nonpolar solutes yaj zoo nyob rau hauv nonpolar solvents. Tab sis solubility ntawm polar solutes nyob rau hauv nonpolar solvents (thiab vice versa) yog tsis zoo.
Daim duab 01: Kev daws ntawm Sodium Cation hauv dej
Thaum nws los txog rau thermodynamics, kev daws teeb meem yog ua tau (spontaneous) tsuas yog tias Gibbs lub zog ntawm qhov kev daws zaum kawg qis dua tus neeg Gibbs lub zog ntawm cov kuab tshuaj thiab cov kuab tshuaj. Yog li ntawd, Gibbs dawb zog yuav tsum yog tus nqi tsis zoo (Gibbs dawb lub zog ntawm lub cev yuav tsum tau txo qis tom qab tsim cov tshuaj). Txoj kev daws teeb meem suav nrog cov kauj ruam sib txawv nrog lub zog sib txawv.
- Kev tsim cov kab noj hniav ntawm cov kuab tshuaj los ua qhov chaw rau cov kuab tshuaj. Qhov no yog thermodynamically tsis zoo vim hais tias thaum kev sib cuam tshuam ntawm cov kuab tshuaj molecule raug txo, thiab cov entropy txo.
- Kev sib cais ntawm cov khoom sib cais los ntawm cov khoom lag luam kuj yog qhov tsis zoo rau thermodynamically. Qhov ntawd yog vim qhov kev sib cuam tshuam-solute txo qis.
- Kev sib cuam tshuam ntawm cov kuab tshuaj tshwm sim thaum cov kuab tshuaj nkag mus rau hauv cov kuab tshuaj yog qhov zoo tshaj plaws thermodynamically.
Kev daws lub zog tseem hu ua enthalpy ntawm kev daws teeb meem. Nws yog qhov tsim nyog los piav qhia txog kev sib cais ntawm qee cov lattices hauv cov kuab tshuaj thaum qee cov lattices tsis. Kev hloov pauv ntawm enthalpy ntawm kev daws yog qhov sib txawv ntawm lub zog ntawm kev tso tawm cov kuab tshuaj los ntawm cov khoom loj thiab sib txuas cov kuab tshuaj nrog cov kuab tshuaj. Yog hais tias ib qho ion muaj qhov tsis zoo rau qhov kev hloov pauv ntawm enthalpy, nws qhia tau tias cov ion feem ntau yuav yaj hauv cov kuab tshuaj ntawd. Tus nqi zoo siab qhia tau tias cov ion tsawg dua yuav yaj.
Lattice Energy yog dab tsi?
Lattice zog yog ib qho kev ntsuas ntawm lub zog uas muaj nyob rau hauv cov siv lead ua lattice ntawm ib tug compound, sib npaug zos rau lub zog uas yuav tso tawm yog hais tias cov khoom ions raug coj los ua ke los ntawm infinity. Lub zog lattice ntawm ib qho chaw kuj tseem tuaj yeem txhais tau tias lub zog xav tau los rhuav tshem cov khoom ionic rau hauv nws cov atoms hauv theem gaseous.
Ionic cov khib nyiab yog cov sib txuas ruaj khov vim yog cov enthalpies ntawm kev tsim cov ionic molecules nrog rau kev ruaj ntseg vim lub zog lattice ntawm cov qauv khoom. Tab sis lub zog lattice tsis tuaj yeem ntsuas kev sim. Yog li ntawd, lub voj voog yug-Haber yog siv los txiav txim siab lub zog lattice ntawm ionic solids. Muaj ob peb nqe lus yuav tsum nkag siab ua ntej kos ib lub voj voog Yug-Haber.
- Ionization zog - Tus nqi ntawm lub zog yuav tsum tau tshem tawm ib qho hluav taws xob los ntawm qhov nruab nrab atom hauv gaseous
- Electron affinity - Tus nqi ntawm lub zog uas tau tso tawm thaum lub tshuab hluav taws xob ntxiv rau qhov nruab nrab atom hauv cov pa roj
- Lub zog sib cais - Tus nqi ntawm lub zog xav tau los ua kom sib cais ib qho sib xyaw rau hauv atoms lossis ions.
- Sublimation zog - Tus nqi ntawm lub zog xav tau los hloov cov khoom rau hauv nws cov vapour
- Lub tshav kub ntawm kev tsim - Qhov kev hloov ntawm lub zog thaum lub compound yog tsim los ntawm nws cov ntsiab.
- Hess txoj cai - Txoj cai lij choj uas hais tias tag nrho cov kev hloov pauv hauv lub zog ntawm ib qho txheej txheem tuaj yeem txiav txim siab los ntawm kev rhuav tshem cov txheej txheem mus rau ntau kauj ruam.
Daim duab 02: Lub voj voog yug-Haber rau kev tsim cov lithium fluoride (LiF)
Lub voj voog Yug-Haber tuaj yeem muab los ntawm qhov sib npaug hauv qab no.
Kub ntawm kev tsim=cua sov ntawm atomization + Dissociation zog + sum ntawm ionization energies + sum ntawm electron affinities + lattice zog
Tom qab ntawd lub zog lattice ntawm ib qho sib xyaw tuaj yeem tau los ntawm kev hloov kho qhov sib npaug hauv qab no.
Lattice zog=tshav kub ntawm kev tsim - {kub ntawm atomization + Dissociation zog + sum ntawm ionization energies + sum ntawm electron affinities}
Dab tsi yog qhov txawv ntawm Solvation Energy thiab Lattice Energy?
Txoj Kev Zog vs Lattice Zog |
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| Kev daws lub zog yog qhov hloov pauv hauv Gibbs lub zog thaum ib qho ion lossis molecule raug pauv los ntawm lub tshuab nqus tsev (los yog theem roj) mus rau qhov hnyav. | Lattice zog yog ib qho kev ntsuas ntawm lub zog uas muaj nyob rau hauv cov siv lead ua lattice ntawm ib lub compound, sib npaug ntawm lub zog uas yuav tso tawm yog hais tias cov khoom ions raug coj los ua ke los ntawm infinity. |
| Txoj Cai | |
| Kev daws lub zog muab qhov kev hloov pauv ntawm enthalpy thaum soluble hauv cov kuab tshuaj. | Lattice zog muab qhov kev hloov ntawm enthalpy thaum tsim (los yog tawg) ntawm lub lattice. |
Summary – Solvation Energy vs Lattice Energy
Kev daws lub zog yog qhov hloov pauv ntawm enthalpy ntawm lub kaw lus thaum lub sij hawm kev daws teeb meem ntawm cov kuab tshuaj hauv cov kuab tshuaj. Lattice zog yog tus nqi ntawm lub zog tso tawm thaum lub sij hawm tsim ib lub lattice los yog tus nqi ntawm lub zog uas yuav tsum tau ua kom puas lub lattice. Qhov sib txawv ntawm kev daws lub zog thiab lub zog lattice yog tias lub zog kev daws teeb meem muab qhov hloov pauv ntawm enthalpy thaum dissolving ib qho kuab tshuaj nyob rau hauv ib qho hnyav whereas lattice zog muab qhov kev hloov ntawm enthalpy thaum tsim (los yog tawg) ntawm lub lattice.
