Crystalization vs nag lossis daus
Crystalization thiab nag lossis daus yog ob lub ntsiab lus zoo sib xws, uas yog siv los ua kev sib cais. Hauv ob txoj hauv kev, cov khoom kawg yog ib qho khoom thiab nws qhov xwm txheej tuaj yeem tswj tau los ntawm kev tswj hwm qhov sib txawv ntawm cov txheej txheem.
nag xob nag cua
Precipitates yog cov khoom uas muaj cov khoom hauv cov tshuaj. Qee zaum cov khib nyiab yog tshwm sim los ntawm cov tshuaj tiv thaiv hauv cov tshuaj. Cov khoom no thaum kawg yuav nyob rau hauv vim lawv qhov ntom, thiab nws yog hu ua precipitate. Nyob rau hauv centrifugation, lub resulting precipitate kuj hu ua pellet. Cov tshuaj saum toj no cov nag lossis daus yog hu ua supernatant. Lub particle loj nyob rau hauv precipitate hloov ntawm lub sij hawm mus rau lub sij hawm. Colloidal suspensions muaj cov khoom me me, uas tsis nyob hauv, thiab tsis tuaj yeem lim tau yooj yim. Crystals tuaj yeem lim tau yooj yim, thiab lawv loj dua.
Txawm hais tias ntau tus kws tshawb fawb tau tshawb fawb txog cov txheej txheem ntawm precipitate tsim, cov txheej txheem tseem tsis tau nkag siab tag nrho. Txawm li cas los xij, nws tau pom tias qhov loj me me ntawm cov nag lossis daus yog cuam tshuam los ntawm cov dej nag 'solubility, kub, reactant concentrations thiab tus nqi ntawm cov reactants sib xyaw. Precipitates tuaj yeem tsim nyob rau hauv ob txoj kev; los ntawm nucleation thiab particle loj hlob. Hauv nucleation, ob peb ions, atoms lossis molecules tuaj ua ke los tsim cov khoom ruaj khov. Cov khoom me me no hu ua nuclei. Feem ntau, cov nuclei tsim nyob rau saum npoo ntawm cov khoom raug tshem tawm. Thaum cov nucleus no nthuav tawm ntxiv rau cov ions, atoms lossis molecules, ntxiv nucleation lossis kev loj hlob ntxiv ntawm cov khoom tuaj yeem tshwm sim. Yog hais tias nucleation tseem tshwm sim, ib qho precipitate uas muaj ntau qhov me me tshwm sim. Piv txwv li, yog tias kev loj hlob predominates, ib qho me me ntawm cov khoom loj yog tsim. Nrog rau tus txheeb ze super saturation, tus nqi ntawm nucleation nce. Feem ntau, nag lossis daus tshwm sim qeeb. Yog li ntawd, thaum lub precipitating reagent yog ntxiv maj mam mus rau ib qho kev daws teeb meem ntawm ib qho analyte, ib tug super saturation yuav tshwm sim. (Supersaturated tov yog cov tshuaj tsis ruaj khov uas muaj cov kuab tshuaj ntau dua li cov tshuaj saturated.)
Crystalization
Crystalization yog cov txheej txheem ntawm precipitating crystals los ntawm kev daws vim muaj kev hloov pauv hauv cov kua dej ntawm cov kua dej hauv cov tshuaj. Qhov no yog ib txoj kev sib cais zoo ib yam li nag lossis daus. Qhov txawv ntawm txoj kev no los ntawm cov nag lossis daus ib txwm yog tias, cov khoom tshwm sim yog siv lead ua. Crystalline precipitates yog lim tau yooj yim dua thiab huv. Cov siv lead ua particle loj tuaj yeem txhim kho los ntawm kev siv cov tshuaj dilute thiab ntxiv cov precipitating reagent maj mam thaum sib tov. Qhov zoo ntawm cov siv lead ua thiab kev txhim kho hauv filterability tuaj yeem tau txais los ntawm kev sib cais thiab rov ua kom rov ua kom rov ua kom zoo dua ntawm cov khoom. Crystallization tuaj yeem pom hauv qhov xwm txheej thiab. Nws yog feem ntau nqa tawm dag rau ntau hom siv lead ua thiab purification.
Qhov txawv ntawm Crystallization thiab nag lossis daus yog dab tsi?
• Ob nqe lus no txawv vim lawv cov khoom kawg. Nyob rau hauv crystallization, muaju yog tsim thiab nyob rau hauv nag lossis daus amorphous solids yog tsim.
• Crystals muaj cov qauv txiav txim dua li cov khoom amorphous; yog li ntawd, nws yog ib qho nyuaj rau tsim crystals. Yog li, crystallization nyuaj dua los nag.
• txheej txheem crystallization yuav siv sij hawm ntau dua cov txheej txheem los nag.
