Cov kev daws teeb meem yog homogeneous systems uas muaj ob lossis ntau yam khoom, nrog rau cov khoom uas yog qhov tshwm sim ntawm kev sib cuam tshuam ntawm cov khoom no. Lawv tuaj yeem nyob hauv cov khoom, kua lossis gaseous xeev. Xav txog cov kua lub xeev ntawm aggregation ntawm kev daws. Lawv suav nrog cov kuab tshuaj thiab cov tshuaj yaj hauv nws (tom kawg tsawg dua).
Cov khoom sib koom ua ke ntawm cov kev daws teeb meem yog lawv cov yam ntxwv uas ncaj qha nyob ntawm qhov hnyav thiab qhov concentration ntawm cov tshuaj. Lawv kuj hu ua collective los yog common. Lub colligative zog ntawm kev daws yog manifested nyob rau hauv sib tov nyob rau hauv uas tsis muaj kev sib cuam tshuam ntawm ib tug tshuaj xwm ntawm lawv cov constituent Cheebtsam. Tsis tas li ntawd, lub zog ntawm kev sib koom ua ke ntawm cov khoom ntawm cov kuab tshuaj thiab cov khoom ntawm cov kuab tshuaj thiab cov tshuaj yaj hauv nws yog sib npaug hauv cov kev daws teeb meem zoo tshaj plaws.
Coligative properties of solutions:
1) Lub vapor siab yog qis dua cov tshuaj dua li cov kuab tshuaj.
2) Crystallization ntawm cov tshuaj tshwm sim ntawm qhov kub thiab txias hauv qab crystallization kub ntawm cov kuab tshuaj nyob rau hauv nws daim ntawv ntshiab.
3) Cov tshuaj boils ntawm qhov kub siab tshaj qhov hnyav nws tus kheej.
4) Phenomenonosmosis.
Cia peb xav txog kev sib koom ua ke sib cais.
Sib npaug ntawm theem ciam teb nyob rau hauv lub kaw lus kaw: kua - vapor yog tus cwj pwm los ntawm saturated vapor siab. Txij li ib feem ntawm cov txheej txheej saum npoo hauv cov tshuaj tau ntim nrog cov kua nplaum molecules, qhov sib npaug yuav ua tiav ntawm qhov qis qis dua.
Qhov thib ob colligative khoom - qhov txo qis hauv crystallization kub ntawm cov tshuaj piv rau cov kuab tshuaj - yog vim qhov tseeb hais tias cov khoom ntawm cov kuab tshuaj cuam tshuam nrog kev tsim cov muaju thiab yog li tiv thaiv crystallization thaum kub txo..
Lub ntsiab lus kub ntawm qhov sib xyaw yog siab dua li cov kuab tshuaj hauv nws daim ntawv ntshiab, vim tias qhov sib npaug ntawm atmospheric siab thiab saturated vapor siab tau ua tiav nrog cov cua sov ntau dua, vim qee qhov hnyav molecules cuam tshuam nrog particles ntawm yaj tshuaj.
Plaub yam cuab yeej ntawm kev daws teeb meem yog qhov tshwm sim ntawm osmosis.
Qhov tshwm sim ntawm osmosis yog lub peev xwm ntawm cov kuab tshuaj los ntawm kev faib tawm uas yog permeable rau qee cov khoom (hloov molecules) thiab impermeable rau lwm tus (cov kuab tshuaj molecules). Qhov kev faib tawm no cais cov kev daws teeb meem nrog cov ntsiab lus siab ntawm cov ntsiab lus los ntawm cov tshuaj tsis tshua muaj siab. Ib qho piv txwv ntawm xws li ib tug semi-permeable muab faib yog lub membrane ntawm ib tug nyob cell, bovine zais zis, thiab lwm yam. Qhov tshwm sim ntawm osmosis yog vim qhov sib npaug ntawm cov concentrations ntawm ob sab, sib cais los ntawm ib daim nyias nyias, uas yog.thermodynamically zoo dua rau qhov system. Vim lub zog ntawm cov kuab tshuaj mus rau hauv ib qho kev daws teeb meem ntau dua, kev nce siab hauv cov hlab ntsha no tau pom. Qhov siab tshaj no hu ua osmotic siab.
Cov khoom sib koom ua ke ntawm cov kev daws teeb meem tsis yog electrolyte tuaj yeem ua lej sawv cev los ntawm qhov sib npaug:
∆ Tbp.=Equip∙See;
∆ Tcr.=Kzam∙Sm;
π=CRT.
Cov khoom sib koom ua ke hauv cov lej sib txawv rau cov tshuaj electrolyte thiab cov tshuaj tsis yog electrolyte. Rau thawj, lawv yog me ntsis loj dua. Qhov no yog vim qhov tseeb tias electrolytic dissociation tshwm sim nyob rau hauv lawv, thiab tus naj npawb ntawm cov particles nce ho.
Cov khoom sib xyaw ua ke ntawm kev daws teeb meem tau siv dav hauv lub neej txhua hnub thiab hauv kev tsim khoom, piv txwv li, qhov tshwm sim ntawm osmosis yog siv kom tau txais cov dej huv. Hauv cov kab mob uas muaj sia nyob, ntau lub tshuab kuj tau tsim los ntawm kev sib koom ua ke ntawm kev daws teeb meem (piv txwv li, kev loj hlob ntawm cov nroj tsuag hlwb).
