Puas muaj ntau yam tshuaj dawb huv nyob rau hauv cov xwm txheej? Dab tsi yog dej hiav txwv, mis nyuj, hlau xaim - cov khoom ntawm tus kheej, lossis lawv puas muaj ntau yam khoom? Nyob rau hauv peb tsab xov xwm, peb yuav tau paub txog cov khoom ntawm kev daws teeb meem - cov feem ntau physico-chemical systems uas muaj ib tug sib txawv muaj pes tsawg leeg. Lawv tuaj yeem muaj ntau yam khoom siv. Yog li, mis nyuj yog ib qho organic tov uas muaj dej, tee roj, protein molecules thiab ntxhia ntsev. Dab tsi yog qhov kev daws teeb meem thiab nws tuaj yeem tau txais li cas? Peb yuav teb cov lus nug no thiab lwm cov lus nug hauv peb tsab xov xwm.
Kev siv cov kev daws teeb meem thiab lawv lub luag haujlwm hauv xwm
Metabolism hauv biogeocenoses yog ua los ntawm kev sib cuam tshuam ntawm cov tebchaw yaj hauv dej. Piv txwv li, kev nqus ntawm cov av daws los ntawm cov hauv paus hniav, cov hmoov txhuv nplej siab ntau ntxiv los ntawm photosynthesis hauv cov nroj tsuag, cov txheej txheem zom zaub mov ntawm cov tsiaj thiab tib neeg - tag nrho cov ntawm lawv yog cov tshuaj tiv thaiv uas tshwm sim hauv cov tshuaj lom neeg. Nws yog tsis yooj yim sua xav txog tej yam niaj hnub kev lag luam: chaw thiab aircraft kev lag luam, tub rog kev lag luam, nuclear zogtsis siv cov alloys - cov kev daws teeb meem nrog cov yam ntxwv tshwj xeeb. Ob peb gases kuj tuaj yeem tsim cov khoom sib tov, uas peb tuaj yeem hu ua kev daws teeb meem. Piv txwv li, huab cua yog lub cev thiab tshuaj lom neeg uas muaj cov khoom xws li nitrogen, oxygen, carbon dioxide, thiab lwm yam.
kev daws yog dab tsi?
Los ntawm kev sib xyaw ua ke sulfate acid thiab dej, peb tau txais nws cov tshuaj aqueous. Xav txog qhov nws muaj. Peb yuav pom cov kuab tshuaj - dej, cov kuab tshuaj - sulfuric acid thiab cov khoom ntawm lawv cov kev sib cuam tshuam. Cov no suav nrog hydrogen cations, hydrosulfate - thiab sulfate ions. Lub cev muaj pes tsawg leeg ntawm cov tshuaj physico-chemical, uas muaj cov kuab tshuaj thiab cov khoom, yuav nyob ntawm seb yam khoom twg yog qhov hnyav.
Cov kuab tshuaj tseem ceeb tshaj plaws yog dej. Qhov xwm txheej ntawm cov khoom tawg tau kuj tseem ceeb heev. Lawv tuaj yeem muab faib ua peb pawg. Cov no yog cov sib xyaw ua ke insoluble, me ntsis soluble thiab soluble heev. Cov pab pawg kawg yog qhov tseem ceeb tshaj plaws. Nws suav nrog feem ntau ntsev, acids, alkalis, cawv, monosaccharides. Poorly soluble compounds kuj muaj nyob rau hauv cov xwm. Cov no yog gypsum, nitrogen, methane, oxygen. Xyaum insoluble hauv dej yuav yog hlau, noble gases: argon, helium, thiab lwm yam., kerosene, roj.
Yuav ua li cas ntsuas qhov solubility ntawm ib qho compound
Qhov concentration ntawm cov tshuaj saturated yog tus nqi tseem ceeb tshaj plaws uas qhia txog kev solubility ntawm ib yam khoom. Nwsqhia raws li tus nqi tus lej sib npaug rau qhov loj ntawm qhov sib xyaw hauv 100 g ntawm kev daws. Piv txwv li, cov khoom siv tshuaj tua kab mob - salicylic cawv yog muag hauv khw muag tshuaj hauv daim ntawv ntawm 1% cawv tov. Qhov no txhais tau hais tias 100 g ntawm cov tshuaj muaj 1 gram ntawm cov tshuaj nquag. Dab tsi yog qhov loj tshaj plaws ntawm sodium chloride uas tuaj yeem yaj hauv 100 g ntawm cov kuab tshuaj ntawm qhov kub thiab txias? Koj tuaj yeem nrhiav tau cov lus teb rau lo lus nug no siv lub rooj tshwj xeeb ntawm solubility curves rau cov khoom sib txuas. Yog li, ntawm qhov kub ntawm 10 ⁰С, 38 g ntawm lub rooj ntsev tuaj yeem yaj hauv 100 g dej, ntawm 80 ⁰С - 40 g ntawm cov khoom. Yuav ua li cas kom daws tau dilute? Koj yuav tsum tau ntxiv ib qho dej rau nws. Nws muaj peev xwm ua kom cov concentration ntawm physicochemical system los ntawm evaporating cov tshuaj, los yog los ntawm kev ntxiv ib feem ntawm cov yaj compound rau nws.
Yam kev daws teeb meem
Ntawm qhov kub thiab txias, lub kaw lus tuaj yeem nyob hauv qhov sib npaug nrog cov txheej txheem yaj hauv daim ntawv ntawm nws cov precipitate. Hauv qhov no, ib tus hais txog kev daws teeb meem saturated. Yuav ua li cas kom daws tau qhov saturated? Ua li no, xa mus rau lub rooj ntawm solubility ntawm cov khib nyiab. Piv txwv li, lub rooj ntsev uas hnyav 31 g yog nkag rau hauv dej ntawm qhov kub ntawm 20 ºС thiab ib txwm siab, ces nws yog zoo stirred. Nrog rau cov cua sov ntxiv thiab kev taw qhia ntawm ib feem ntxiv ntawm ntsev, nws qhov ntau dhau ua kom muaj cov tshuaj supersaturated. Qhov txias ntawm lub kaw lus yuav ua rau cov txheej txheem ntawm nag lossis daus ntawm sodium chloride crystals. Cov tshuaj diluted yuav raug hu ua cov kev daws teeb meem uas qhov concentration ntawm cov ntsiab lus sib piv nrog cov ntim ntawm cov kuab tshuaj yuav yogme me txaus. Piv txwv li, saline, uas yog ib feem ntawm cov ntshav plasma thiab siv nyob rau hauv cov tshuaj tom qab kev phais kev phais, yog ib tug 0.9% sodium chloride tov.
Mechanism of substance dissolution
Tom qab xav txog cov lus nug ntawm qhov kev daws teeb meem yog dab tsi, cia peb txiav txim siab dab tsi cov txheej txheem underlie nws tsim. Hauv plawv ntawm qhov tshwm sim ntawm kev sib cais ntawm cov khoom, peb pom kev sib cuam tshuam ntawm ob qho tib si lub cev thiab tshuaj hloov pauv. Lub luag haujlwm tseem ceeb hauv lawv yog ua si los ntawm qhov tshwm sim ntawm kev puas tsuaj ntawm cov khoom siv tshuaj lom neeg: covalent polar lossis ionic, nyob rau hauv cov molecules ntawm yaj compound. Lub cev nam ntawm daim ntawv cog lus tawg yog qhia nyob rau hauv kev nqus ntawm lub zog. Kuj tseem muaj kev cuam tshuam ntawm cov kuab tshuaj nrog cov kuab tshuaj molecules, hu ua kev daws teeb meem, nyob rau hauv cov ntaub ntawv ntawm aqueous daws - hydration. Nws yog nrog tsis yog los ntawm qhov tshwm sim ntawm cov nyiaj tshiab, tab sis kuj los ntawm kev tso tawm lub zog.
Nyob hauv peb tsab xov xwm, peb tau tshuaj xyuas cov lus nug ntawm qhov kev daws teeb meem yog dab tsi, thiab tseem pom cov txheej txheem rau kev tsim cov kev daws teeb meem thiab lawv qhov tseem ceeb.
