Kev daws yog homogeneous pawg lossis sib xyaw uas muaj ob lossis ntau yam khoom, uas ib yam khoom ua raws li hnyav, thiab lwm yam ua cov khoom soluble.
Muaj ob txoj kev xav ntawm kev txhais lus ntawm lub hauv paus ntsiab lus ntawm kev daws teeb meem: tshuaj lom neeg, tus tsim uas yog D. I. Mendeleev, thiab lub cev, npaj los ntawm German thiab Swiss physicists Ostwald thiab Arrhenius. Raws li Mendeleev txoj kev txhais, cov khoom ntawm cov kuab tshuaj thiab cov kuab tshuaj los ua cov neeg koom nrog cov tshuaj tiv thaiv nrog kev tsim cov tshuaj tsis ruaj khov ntawm cov khoom no lossis cov khoom siv.
Lub cev txoj kev xav tsis lees paub cov tshuaj lom neeg sib cuam tshuam ntawm cov molecules ntawm cov kuab tshuaj thiab cov tshuaj yaj, piav qhia txog cov txheej txheem ntawm kev tsim cov kev daws teeb meem raws li kev sib faib ntawm cov khoom (molecules, ions) ntawm cov kuab tshuaj ntawm cov khoom ntawm cov yaj. tshuaj vim yog lub cev tshwm sim hu ua diffusion.
Kev faib cov kev daws teeb meem raws li ntau yam qauv
Hnub no tsis muaj kev sib koom ua ke rau kev daws teeb meem, txawm li cas los xij, cov xwm txheej, cov kev daws teeb meem tuaj yeem ua pawg raws li cov txheej txheem tseem ceeb, xws li:
I) Raws li lub xeev ntawm kev sib sau ua ke, cov khoom sib xyaw, cov roj av thiab cov kua dej sib txawv.
II) BySolute particle loj: colloidal thiab muaj tseeb.
III) Raws li qib ntawm concentration ntawm cov khoom ntawm cov kuab tshuaj hauv cov tshuaj: saturated, unsaturated, concentrated, dilute.
IV) Raws li lub peev xwm ua hluav taws xob tam sim no: electrolytes thiab non-electrolytes.
V) Los ntawm lub hom phiaj thiab qhov dav: tshuaj lom neeg, kev kho mob, kev tsim kho, kev daws teeb meem tshwj xeeb, thiab lwm yam.
Yam kev daws teeb meem los ntawm lub xeev ntawm kev sib sau
Kev faib cov kev daws teeb meem raws li lub xeev ntawm kev sib sau ua ke ntawm cov kuab tshuaj yog muab rau hauv qhov dav dav ntawm lub ntsiab lus ntawm lo lus no. Nws yog kev cai los txiav txim siab txog cov kua tshuaj raws li kev daws teeb meem (tsis tas li ntawd, ob qho tib si cov kua thiab cov khoom muaj peev xwm ua tau raws li cov kuab tshuaj), tab sis yog tias peb coj mus rau hauv tus account qhov tseeb hais tias cov tshuaj yog ib homogeneous system ntawm ob los yog ntau tshaj cov tshuaj, ces nws yog. logic heev kom paub txog cov kev daws teeb meem, thiab gaseous. Cov kev daws teeb meem yog suav tias yog kev sib xyaw ntawm, piv txwv li, ntau cov hlau, paub zoo dua hauv lub neej niaj hnub li alloys. Gaseous hom kev daws teeb meem yog sib tov ntawm ob peb gases, piv txwv li yog huab cua nyob ib ncig ntawm peb, uas yog nthuav tawm raws li ib tug ua ke ntawm oxygen, nitrogen thiab carbon dioxide.
Kev daws los ntawm qhov loj me
Hom kev daws teeb meem los ntawm qhov loj me ntawm cov khoom tawg muaj xws li cov kev daws teeb meem tiag tiag (xeem) thiab cov tshuab colloidal. Hauv cov kev daws teeb meem tiag tiag, cov kuab tshuaj tawg mus rau hauv cov molecules me lossis atoms uas nyob ze rau qhov loj me rau cov molecules ntawm cov kuab tshuaj. Nyob rau tib lub sijhawm, qhov tseeb hom kev daws teeb meem khaws cov khoom qub ntawm cov kuab tshuaj, tsuas yog me ntsistransforming nws nyob rau hauv qhov kev txiav txim ntawm lub physicochemical zog ntawm lub caij ntxiv rau nws. Piv txwv li: thaum ntsev los yog qab zib yaj nyob rau hauv dej, cov dej tseem nyob rau hauv tib lub xeev ntawm aggregation thiab tib yam sib xws, yuav luag tib xim, tsuas yog nws saj hloov.
Colloid cov kev daws teeb meem sib txawv ntawm cov khoom siv nyob rau hauv uas cov khoom siv ntxiv tsis ua kom tawg tag, khaws cov molecules complex thiab cov tebchaw, qhov loj ntawm qhov loj dua li cov kuab tshuaj, tshaj tus nqi ntawm 1 nanometer.
Yam tshuaj concentration
Nyob rau hauv tib tus nqi ntawm cov kuab tshuaj, koj tuaj yeem ntxiv qhov sib txawv ntawm cov khoom tawg, cov zis yuav muaj cov kev daws teeb meem nrog ntau qhov sib txawv. Peb teev cov tseem ceeb:
- Cov tshuaj saturated yog tus cwj pwm los ntawm qib ntawm kev solubility ntawm ib yam khoom, ntawm qhov uas cov khoom tawg, nyob rau hauv tus nqi ntawm qhov kub thiab txias tsis tu ncua, tsis decomposes rau hauv atoms thiab molecules, thiab cov tshuaj mus txog theem equilibrium.. Saturated solutions kuj yuav conditionally muab faib ua concentrated, nyob rau hauv uas cov loj feem ntawm cov yaj tivthaiv yog piv rau cov hnyav, thiab dilute, qhov twg cov kuab tshuaj yog ob peb zaug tsawg dua cov kuab tshuaj.
- Unsaturated yog cov kev daws teeb meem uas cov kuab tshuaj tseem tuaj yeem decompose rau hauv cov khoom me me.
- Supersaturated cov kev daws teeb meem tau txais thaum qhov tsis muaj qhov cuam tshuam (kub, siab) hloov, vim tias cov txheej txheem ntawm "crushing" ntawm cov yaj. Cov khoom, nws dhau los ua ntau dua li nws nyob rau hauv ib txwm muaj (ib txwm) yam.
Electrolytes thiab non-electrolytes
Qee yam hauv cov tshuaj decompose rau hauv ions muaj peev xwm ua hluav taws xob tam sim no. Xws li homogeneous systems hu ua electrolytes. Cov pab pawg no suav nrog cov kua qaub, feem ntau cov ntsev. Thiab cov kev daws teeb meem uas tsis ua hluav taws xob tam sim no feem ntau hu ua non-electrolytes (yuav luag tag nrho cov organic tebchaw).
Pab pawg kev daws teeb meem los ntawm lub hom phiaj
Cov kev daws teeb meem yog qhov tseem ceeb hauv txhua txoj haujlwm ntawm kev lag luam hauv lub tebchaws, qhov tshwj xeeb uas tau tsim cov kev daws teeb meem tshwj xeeb xws li kev kho mob, kev tsim kho, tshuaj lom neeg thiab lwm yam.
Cov tshuaj kho mob yog cov tshuaj sau los ntawm cov tshuaj pleev, tshem tawm, sib tov, kev daws rau infusions thiab txhaj tshuaj thiab lwm yam tshuaj siv rau kev kho mob rau kev kho mob thiab tiv thaiv ntau yam kab mob.
Hom tshuaj daws teeb meem suav nrog ntau yam sib xyaw ua ke uas siv rau hauv cov tshuaj tiv thaiv: acids, ntsev. Cov kev daws teeb meem no tuaj yeem yog cov organic lossis inorganic keeb kwm, aqueous (dej hiav txwv) los yog anhydrous (raws li benzene, acetone, thiab lwm yam), kua (vodka) los yog khoom (tooj dag). Lawv tau pom lawv daim ntawv thov nyob rau hauv ntau yam kev lag luam hauv lub tebchaws: tshuaj lom neeg, zaub mov, kev lag luam textile.
Hom mortars muaj viscous thiab tuab sib xws, uas yog vim li cas lawv thiaj li tsim nyog rau lub npe sib xyaw.
Vim lawv muaj peev xwm ua kom tawv sai, lawv tau ua tiav siv los ua cov ntaub ntawv rau cov phab ntsa masonry, qab nthab, cov khoom thauj khoom, nrog rau kev ua haujlwm tiav. Lawv yog cov kev daws teeb meem aqueous, feem ntau yog peb lub ntsiab lus (cov kuab tshuaj, cov cement ntawm ntau cov cim, sib sau), qhov twg cov xuab zeb, av nplaum, crushed pob zeb, txiv qaub, gypsum thiab lwm yam khoom siv hauv tsev yog siv los ua ib qho muab tub lim.
