Cov tshuaj dawb huv yuav luag tsis pom nyob hauv qhov xwm txheej. Yeej, lawv tau nthuav tawm hauv daim ntawv sib xyaw uas muaj peev xwm tsim homogeneous lossis heterogeneous systems.
Txoj kev daws teeb meem tseeb
Txoj kev daws teeb meem yog ib hom kev sib cais uas muaj lub zog ntau dua ntawm qhov nruab nrab dispersion thiab theem dispersed.
Crystals ntawm ntau qhov sib txawv tuaj yeem tau txais los ntawm txhua yam tshuaj lom neeg. Txawm li cas los xij, lawv yuav muaj tib lub qauv sab hauv: ionic lossis molecular crystal lattice.
Dissolve
Nyob rau hauv cov txheej txheem ntawm cov nplej zom ntawm sodium chloride thiab qab zib hauv dej, ib qho ionic thiab molecular tov yog tsim. Nyob ntawm qhov degree ntawm fragmentation, cov khoom yuav ua tau nyob rau hauv daim ntawv:
- pom macroscopic hais loj dua 0.2 hli;
- microscopic particles me dua 0.2 mm tuaj yeem ntes tau nrog lub tshuab tsom.
Qhov tseeb thiab cov tshuaj colloidal sib txawv ntawm qhov loj ntawm cov khoom ntawm cov kua nplaum. Crystals tsis pom nyob rau hauv lub tshuab tsom iav yog hu ua colloidal hais, thiab lub xeev tshwm sim yog hu ua cov tshuaj colloidal.
Kev daws teeb meem
Feem ntau, cov kev daws teeb meem tseeb yog crushed (dispersed) systems ntawm homogeneous hom. Lawv muaj ib ntus tas mus li - qhov nruab nrab dispersion, thiab crushed hais ntawm ib tug tej yam duab thiab loj (dispersed theem). Cov kev daws teeb meem colloidal txawv li cas los ntawm cov tshuab muaj tseeb?
Qhov sib txawv tseem ceeb yog qhov loj me. Colloidal-dispersed systems yog suav tias yog heterogeneous, vim nws tsis yooj yim sua kom ntes cov theem ciam teb hauv lub teeb tsom iav.
Cov kev daws teeb meem tseeb - qhov no yog qhov kev xaiv thaum nyob hauv ib puag ncig cov khoom muaj nyob rau hauv daim ntawv ntawm ions lossis molecules. Lawv xa mus rau cov kev daws teeb meem ib-theem homogeneous.
Kev sib tshuam ntawm qhov nruab nrab dispersion thiab cov khoom tawg yog suav tias yog qhov tsim nyog rau kev tsim cov tshuab tawg. Piv txwv li, sodium chloride thiab sucrose yog insoluble nyob rau hauv benzene thiab kerosene, yog li colloidal daws yuav tsis tsim nyob rau hauv xws li hnyav.
Kev faib tawm ntawm cov kab ke sib cais
Cov kab ke sib cais faib li cas? Cov kev daws teeb meem tiag tiag, cov tshuab colloidal sib txawv ntawm ntau txoj hauv kev.
Muaj kev faib tawm ntawm cov txheej txheem sib cais raws li lub xeev ntawm kev sib sau ua ke ntawm nruab nrab thiab theem tawg, tsim lossis tsis muaj kev cuam tshuam ntawm lawv.
Ntse
Muaj qee yam yam ntxwv ntawm qhov sib txawv ntawm cov khoom. Ua ntej tshaj plaws, qhov degree ntawm dispersion yog qhov txawv. Tus nqi no yog qhov sib npaug ntawm cov particle loj. Nws yogcharacterizes tus naj npawb ntawm cov khoom uas tuaj yeem muab tso rau hauv kab ntawm qhov deb ntawm ib centimeter.
Nyob rau hauv rooj plaub thaum tag nrho cov particles muaj tib lub loj, ib tug monodisperse system yog tsim. Nrog rau qhov tsis sib xws ntawm cov theem dispersed, ib qho txheej txheem polydisperse yog tsim.
Nrog rau kev nce hauv kev tawg ntawm ib yam khoom, cov txheej txheem uas tshwm sim hauv qhov chaw ntawm lub ntsej muag nce hauv nws. Piv txwv li, qhov tshwj xeeb nto ntawm cov theem dispersed nce, cov nyhuv physicochemical ntawm qhov nruab nrab ntawm qhov sib cuam tshuam ntawm ob theem nce.
Variants of disperse systems
Nyob ntawm theem uas tus solute yuav yog, ntau yam sib txawv ntawm cov tshuab dispersed yog qhov txawv.
Aerosols yog cov tshuab tawg uas qhov nruab nrab dispersed tau nthuav tawm hauv daim ntawv gaseous. Fog yog aerosols muaj cov kua dispersed theem. Cov pa taws thiab plua plav yog tsim los ntawm cov khoom tawg yooj yim.
Ua npuas ncauj yog qhov tawg hauv cov kua ntawm cov khoom siv roj. Cov kua hauv foams degenerate rau hauv cov yeeb yaj kiab uas cais cov pa npuas.
Emulsions yog cov tshuab tawg, qhov twg ib qho kua tau muab faib rau hauv qhov ntim ntawm lwm qhov yam tsis tau yaj hauv nws.
Kev ncua lossis ncua kev kawm ntawv yog cov tshuab qis qis uas cov khoom muaj nyob hauv cov kua. Colloidal solutions los yog sols nyob rau hauv lub aqueous dispersion system yog hu ua hydrosols.
Nyob ntawm qhov muaj (tsis muaj) nruab nrab ntawm cov khoom ntawm cov theem tawg, cov txheej txheem dawb-dispersed lossis coherently dispersed yog qhov txawv. Rau thawj pab pawgmuaj xws li lyosols, aerosols, emulsions, suspensions. Nyob rau hauv xws li systems, tsis muaj kev sib cuag ntawm cov hais thiab cov dispersed theem. Lawv txav mus los ntawm kev daws teeb meem hauv qab lub ntiajteb txawj nqus.
Cohesive-disperse systems tshwm sim nyob rau hauv cov ntaub ntawv ntawm kev sib cuag ntawm hais nrog ib tug dispersed theem, vim hais tias ntawm cov qauv nyob rau hauv daim ntawv ntawm ib daim phiaj los yog ib lub moj khaum yog tsim. Xws li cov tshuab colloidal hu ua gels.
Cov txheej txheem ntawm gelation (gelatinization) yog kev hloov pauv ntawm sol mus rau hauv gel, raws li qhov txo qis hauv kev ruaj ntseg ntawm cov khoom qub. Piv txwv ntawm bonded disperse systems yog suspensions, emulsions, hmoov, foams. Lawv kuj suav nrog cov av tsim nyob rau hauv cov txheej txheem ntawm kev sib cuam tshuam ntawm cov organic (humus) tshuaj thiab cov ntxhia hauv av.
Capillary-dispersed systems yog qhov txawv los ntawm qhov tsis tu ncua ntawm cov teeb meem nkag mus rau capillaries thiab pores. Lawv suav hais tias yog fabrics, nyias nyias, ntoo, cardboard, ntawv.
Txoj kev daws teeb meem yog homogeneous systems uas muaj ob yam. Lawv tuaj yeem muaj nyob rau hauv cov kuab tshuaj ntawm ntau lub xeev ntawm kev sib sau. Cov kuab tshuaj yog ib yam khoom noj ntau dhau. Ib qho khoom noj uas tau noj tsis txaus yog suav tias yog kev daws teeb meem.
Txoj kev daws teeb meem
Cov alloys nyuaj kuj yog cov kev daws teeb meem uas ntau yam hlau ua raws li qhov nruab nrab dispersed thiab tivthaiv. Los ntawm qhov ua tau zoo ntawm qhov pom, tshwj xeeb tshaj yog cov kua sib tov uas cov kua ua kua ua kuab lom.
Los ntawm ntau inorganicCov kuab tshuaj tshwj xeeb yog dej. Yuav luag ib txwm, qhov kev daws teeb meem tiag tiag yog tsim thaum cov khoom ntawm cov kua dej sib xyaw nrog dej.
Ntawm cov organic tebchaw, cov tshuaj hauv qab no yog cov kuab tshuaj zoo heev: ethanol, methanol, benzene, carbon tetrachloride, acetone. Vim lub chaotic txav ntawm cov molecules los yog ions ntawm cov yaj tivthaiv, lawv ib nrab dhau mus rau hauv cov tshuaj, tsim ib tug tshiab homogeneous system.
Cov khoom sib txawv ntawm lawv lub peev xwm los tsim cov kev daws teeb meem. Qee qhov tuaj yeem sib xyaw ua ke hauv qhov tsis muaj qhov txwv. Ib qho piv txwv yog kev sib cais ntawm cov ntsev ntsev hauv dej.
Lub ntsiab lus ntawm cov txheej txheem kev sib cais los ntawm qhov pom ntawm qhov kev xav ntawm molecular-kinetic txoj kev xav yog tias tom qab kev qhia txog sodium chloride crystals rau hauv cov kuab tshuaj, nws dissociates rau hauv sodium cations thiab chlorine anions. Charged hais oscillate, kev sib tsoo nrog cov khoom ntawm cov kuab tshuaj nws tus kheej ua rau kev hloov ntawm ions mus rau hauv cov kuab tshuaj (binding). Maj mam, lwm cov khoom txuas nrog rau cov txheej txheem, txheej txheej saum npoo raug rhuav tshem, cov ntsev ntsev yaj hauv dej. Diffusion tso cai rau kev faib cov khoom ntawm cov khoom thoob plaws hauv lub ntim ntawm cov kuab tshuaj.
Yam kev daws teeb meem
Txoj kev daws teeb meem yog qhov system uas tau muab faib ua ntau hom. Muaj kev faib tawm ntawm cov tshuab no rau hauv aqueous thiab non-aqueous raws li hom hnyav. Lawv kuj raug cais raws li qhov sib txawv ntawm cov kuab tshuaj rau hauv alkalis, acids, ntsev.
Eatntau hom kev daws teeb meem tiag tiag hauv kev cuam tshuam rau hluav taws xob tam sim no: tsis yog-electrolytes, electrolytes. Nyob ntawm qhov concentration ntawm cov kua, lawv tuaj yeem diluted lossis concentrated.
Cov kev daws teeb meem tiag tiag ntawm cov tshuaj tsis tshua muaj molecular los ntawm qhov ntsuas kub ntawm qhov pom tau muab faib ua qhov tiag thiab zoo tagnrho.
Cov kev daws teeb meem zoo li no tuaj yeem ua rau ion-dispersed, nrog rau cov tshuab molecular-dispersed.
Saturation of solutions
Nyob ntawm seb muaj pes tsawg cov khoom nkag mus rau hauv cov tshuaj, muaj supersaturated, unsaturated, saturated daws. Ib qho kev daws teeb meem yog cov kua lossis cov khoom sib xyaw ua ke, uas muaj ntau yam. Nyob rau hauv txhua rooj plaub, ib tug hnyav yuav tsum tam sim no, raws li zoo raws li ib tug solute. Thaum qee cov tshuaj yaj, cua sov tawm.
Cov txheej txheem zoo li no lees paub qhov kev xav ntawm cov kev daws teeb meem, raws li qhov kev sib cais yog suav tias yog txheej txheem ntawm lub cev thiab tshuaj. Muaj kev faib cov txheej txheem solubility ua peb pawg. Thawj yog cov tshuaj uas muaj peev xwm yaj hauv qhov nyiaj ntawm 10 g hauv 100 g ntawm cov kuab tshuaj, lawv hu ua soluble heev.
Cov tshuaj raug suav tias yog me ntsis soluble yog tias tsawg dua 10 g yaj hauv 100 g ntawm cov khoom, tus so yog hu ua insoluble.
Zoo kawg
System uas muaj cov khoom sib txawv ntawm lub xeev ntawm kev sib sau ua ke, qhov loj me, yog qhov tsim nyog rau tib neeg lub neej. Muaj tseeb, cov kev daws teeb meem colloidal, tau tham saum toj no, yog siv loskev tsim tshuaj, khoom noj khoom haus. Paub txog qhov concentration ntawm cov kua qaub, koj tuaj yeem npaj cov kev daws teeb meem tsim nyog, piv txwv li, ethyl cawv lossis acetic acid, rau ntau yam hauv lub neej txhua hnub. Nyob ntawm lub xeev ntawm kev sib sau ua ke ntawm cov kuab tshuaj thiab cov kuab tshuaj, cov tshuab ua haujlwm muaj qee yam ntawm lub cev thiab tshuaj lom neeg.
