Cov Lus Nug Piv Txwv Txog Colloid Thiab Kev Sib Tham
Ib qho colloid yog ib lub kaw lus uas ib yam khoom sib kis thoob plaws lwm yam khoom. Cov txheej txheem colloidal poob ntawm ob qho kawg: cov tshuaj tiag tiag thiab cov tshuaj sib xyaw ua ke. Colloids muaj ntau yam kev siv hauv lub neej txhua hnub thiab kev lag luam, ua rau lawv yog ib qho kev kawm txaus nyiam hauv kev kawm chemistry. Tsab xov xwm no yuav tshawb nrhiav cov piv txwv thiab lawv cov kev sib tham txog colloids kom muab kev nkag siab tob dua.
Kev txhais ntawm Colloid
Ua ntej peb yuav tham txog cov teeb meem piv txwv, nws yog ib qho tseem ceeb uas yuav tsum nkag siab txog cov hauv paus ntawm colloids. Colloids muaj ob theem: theem dispersed (cov khoom uas dispersed) thiab dispersion medium (cov khoom uas theem dispersed raug dispersed). Raws li qhov xwm txheej ntawm kev sib cuam tshuam ntawm theem dispersed thiab dispersion medium, colloids tuaj yeem muab faib ua ntau hom, xws li sols (kua hauv roj), aerosols (khoom lossis kua hauv roj), emulsions (kua hauv kua), thiab gels (khoom hauv kua).
Cov Khoom ntawm Colloids
Colloids muaj ntau yam khoom tshwj xeeb uas sib txawv ntawm cov tshuaj tiag tiag thiab cov tshuaj ncua, uas yog:
- Tyndall Effect: Kev tawg ntawm lub teeb los ntawm cov khoom me me colloidal.
- Kev txav Brownian: kev txav mus los ntawm cov khoom me me hauv cov khoom sib kis.
– Kev sib sau ua ke: Kev sib sau ua ke ntawm cov khoom me me hauv qab qee yam mob, xws li muaj cov electrolytes.
Cov Lus Nug Piv Txwv thiab Kev Sib Tham
Nov yog qee cov piv txwv ntawm cov lus nug thiab kev sib tham txog colloids.
Lo lus nug 1: Tyndall Effect
Lo lus nug: Piav qhia txog lub ntsiab lus ntawm Tyndall Effect hauv cov kab ke colloidal thiab muab piv txwv hauv lub neej txhua hnub.
Kev Sib Tham: Qhov Tyndall effect yog qhov tshwm sim ntawm lub teeb tawg los ntawm cov khoom me me colloidal uas loj txaus los tawg lub teeb tab sis tsis yaj hauv qhov nruab nrab tawg. Qhov no ua rau lub teeb ci ntsa iab hla lub colloid kom zoo li nthuav tawm thiab tsim ib txoj kev ci ntsa iab.
Piv txwv ntawm lub neej txhua hnub:
Ib lub hnub ci ntsa iab los ntawm lub qhov rais thiab dhau los ntawm chav uas muaj hmoov av.
- Cov teeb tsheb ci ntsa iab rau cov pos huab.
Qhov Tyndall effect yog qhov tseem ceeb hauv kev txheeb xyuas cov colloids vim tias cov kev daws teeb meem tiag tiag tsis qhia txog qhov xwm txheej no.
Lo lus nug 2: Brownian Motion
Lo lus nug: Lub ntsiab lus ntawm Brownian motion hauv cov ntsiab lus ntawm colloids yog dab tsi, thiab yuav ua li cas thiaj pom qhov xwm txheej no?
Kev Sib Tham: Kev txav Brownian yog kev txav mus los tsis tu ncua ntawm cov khoom me me colloidal uas tshwm sim vim muaj kev sib tsoo nrog cov molecules ntawm cov khoom sib kis. Kev txav mus los no tau pom thawj zaug los ntawm tus kws tshawb fawb botanical Robert Brown hauv xyoo 1827 thaum nws pom cov noob paj ntoos hauv dej.
Kev Soj Ntsuam ntawm Brownian Motion:
Kev txav ntawm Brownian tuaj yeem pom tau los ntawm kev siv lub tshuab tsom iav ultramicroscope uas tsom mus rau cov khoom me me hauv cov kua nruab nrab. Piv txwv li, cov kua mem uas tawg hauv dej yuav zoo li co thiab txav mus los tsis raws cai thaum pom hauv qab lub tshuab tsom iav.
Kev txav Brownian qhia tau hais tias cov khoom me me colloidal tsis khov sai txawm tias lawv loj dua cov molecules ntawm cov khoom nruab nrab dispersing.
Lo lus nug 3: Hom Colloids
Lus Nug: Hais thiab piav qhia peb hom colloids raws li theem dispersed thiab dispersing medium.
Kev Sib Tham:
1. Hnub Ci:
– Khoom khov hauv kua: Ib qho khoom khov yog ib qho colloid uas cov theem tawg yog cov khoom khov uas tawg hauv cov kua nruab nrab. Piv txwv li suav nrog cov khoom kub thiab cov khoom pleev xim.
– Kua hauv Pa: Cov pa kua yog ib hom huab uas cov kua me me tawg ua pa hauv pa. Piv txwv li suav nrog pos huab thiab huab.
2. Cov tshuaj pleev ib ce:
– Kua hauv Kua: Ib qho emulsion yog ib qho colloid uas cov theem dispersed muaj cov kua me me dispersed hauv ib qho kua nruab nrab. Piv txwv li suav nrog mis nyuj, uas yog cov roj-hauv-dej emulsion, thiab mayonnaise, uas yog cov roj-hauv-dej emulsion.
3. Gel:
– Khoom khov hauv kua: Ib qho gel yog ib qho colloid uas cov theem dispersed muaj cov khoom khov uas nthuav dav thiab nqus dej, tsim ib lub cev semi-rigid. Piv txwv li suav nrog jellies thiab gelatin.
Lo lus nug 4: Kev npaj colloid
Lus Nug: Piav qhia txog cov txheej txheem uas siv tau rau kev npaj colloid thiab muab piv txwv.
Kev Sib Tham: Txoj kev ua cov colloids tuaj yeem muab faib ua ob, uas yog txoj kev sib sau ua ke thiab txoj kev sib kis.
1. Txoj Kev Ua Kom Nqus Dej:
– Cov Tshuaj Tiv Thaiv: Siv cov tshuaj tiv thaiv los tsim cov khoom me me los ntawm cov molecule me me. Piv txwv li: Cov tshuaj tiv thaiv hydrolysis ntawm aluminium chloride tsim cov txhuas hydroxide sol.
– Kev Txo Qhov Kub: Txo qhov kub ntawm cov tshuaj, kom cov solute sib cais ua cov khoom me me thaum qhov kub poob qis. Piv txwv li: Cov pa organic hauv huab cua txias tsim cov aerosols.
2. Txoj Kev Sib Kis:
– Kev Sib Tsoo: Siv lub tshuab sib tsoo lossis lub xuab zeb los faib cov khoom khov kho kom loj li me. Piv txwv li: Ua cov calcium carbonate sol los ntawm kev sib tsoo limestone hauv dej.
– Peptization: Kev ntxiv ib yam khoom uas tuaj yeem tsim tau ib lub colloid los ntawm cov tshuaj sib xyaw ua ke. Piv txwv li: Ntxiv me ntsis HCl rau hauv Fe(OH)3 precipitate hloov nws mus ua Fe(OH)3 sol.
Lo lus nug 5: Colloid Coagulation
Lo lus nug: Lub ntsiab lus ntawm colloid coagulation thiab hais txog ob txoj hauv kev los coagulate colloids.
Kev Sib Tham: Kev sib xyaw ua ke yog cov txheej txheem ntawm cov khoom me me uas sib sau ua ke ua cov khoom loj dua kom lawv thiaj li sib sau ua ke. Cov txheej txheem no tuaj yeem tshwm sim los ntawm qee qhov kev hloov pauv hauv cov xwm txheej, xws li kev ntxiv cov electrolytes lossis kev hloov pauv ntawm qhov kub thiab txias.
Yuav ua li cas kom cov colloids sib xyaw ua ke:
1. Ntxiv Cov Electrolytes: Cov ions los ntawm electrolytes yuav ua rau cov nqi ntawm cov khoom colloidal tsis muaj zog, txo cov zog repulsive ntawm cov khoom me me kom lawv tuaj yeem sib sau ua ke thiab ua rau muaj nag lossis daus. Piv txwv li: Ntxiv NaCl rau AgI sol ua rau coagulation.
2. Kev Ua Kub: Kev ua kom qhov kub thiab txias nce ntxiv yuav ua rau lub zog kinetic ntawm cov khoom me me colloidal nce ntxiv kom kev sib tsoo ntawm cov khoom me me ua ntau zaus thiab muaj zog dua, ua rau lawv sib sau ua ke thiab ua rau muaj nag lossis daus. Piv txwv li: Kev ua kub Fe(OH)3 sol ua rau coagulation.
Los ntawm kev nkag siab thiab ua haujlwm los ntawm cov lus nug saum toj no, vam tias koj yuav txhim kho koj txoj kev nkag siab txog colloids thiab lawv cov khoom. Colloids, ua ib feem tseem ceeb ntawm chemistry, ua lub luag haujlwm tseem ceeb hauv ntau yam kev siv, los ntawm cov khoom noj thiab cov tshuaj pleev ib ce mus rau cov khoom siv high-tech.
