Ukusabalala kwe-methylene blue ne-permanganate: lokho okuboniswa ukuhlolwa kwe-agar

Uthisha usika imigodi emibili epuletini le-agar, agcwalise owodwa ngodayi oluhlaza okwesibhakabhaka nomunye ngesixazululo esinsomi, abese etshela ikilasi ukuthi libuke. Ngemva kwehora, indilinga ensomi isibanzi kakhulu. Ikilasi libhala ukuthi i-potassium permanganate isabalala ngokushesha kune-methylene blue ngoba inemasi encane.

Lowo musho uyiqiniso ngokwengxenye futhi uyadukisa ngokwengxenye, futhi ingxenye edukisayo iyona ethakazelisayo. Lokhu kuboniswa kuyisifundo esivamile sokusabalala, esichazwe ngokwesibonelo kulo msebenzi waselebhu wokuhlola ukusabalala ku-agar, kodwa lokho abafundi abakubonayo akuwona umphumela wemasi yamamolekyuli kuphela. Kuwukuhamba komngcele wombala obonakalayo phakathi kwejeli, okuthonywa ubukhulu bama-ion, ukuzungezwa kwawo ngamanzi, ukubopheka kodayi, ukugxila, izinga lokushisa, nendlela umngcele olinganiswa ngayo.

Umngcele wombala awuyona i-coefficient yokusabalala

Ukusabalala kuwukusuka kwezinhlayiya ezincibilikile endaweni ezinokugxila okuphezulu kuyo ziye endaweni ezinokugxila okuphansi kuyo. I-coefficient yokusabalala, evame ukubhalwa ngokuthi D, ichaza ukuthi lokho kusabalala kwenzeka ngokushesha kangakanani entweni ethile encibilikisiwe, endaweni ethile, nasezingeni elithile lokushisa.

Ipuleti lasekilasini aliyibonisi ngokuqondile i-D. Libonisa umngcele lapho umbala uba buthaka kakhulu ukuba ubonakale. Lowo mngcele uncike emandleni kadayi okumunca ukukhanya, ekukhanyisweni, ekuchayekeni kwekhamera ekukhanyeni, ekugxileni kwesixazululo esifakwe emgodini, nasekwahluleleni komuntu ophethe irula, kanye nasekusabalaleni uqobo.

Biza isilinganiso sasekilasini ngalokho esiyikho: ukuhamba komngcele obonakalayo wokusabalala. Izincazelo ezisemthethweni zihlobanisa isilinganiso sesikwele sebanga lokusuka endaweni yokuqala ne-D ngobudlelwano obufana nalobo obutholakala ekuhlaziyweni kokusabalala ngokukaFick, kodwa ukuthola i-D ngokuvumelanisa imodeli nedatha kudinga amaphrofayili okugxila ngokuhamba kwesikhathi, hhayi ububanzi obubodwa ekupheleni kwesifundo. Olunye ucwaningo lwasekilasini olushicilelwe lwathola i-coefficient yokusabalala kwe-methylene blue kujeli esondele ku-4.5 × 10^-10 m^2/s ngokudweba igrafu yesikwele sebanga uma liqhathaniswa nesikhathi, kunokuqhathanisa ubukhulu bokugcina bamabala. Isithombe esisodwa ngesikhathi esisodwa asikwazi ukwenza lowo msebenzi.

Lona ngumqondo oyisisekelo walokhu kuboniswa, futhi konke okunye kuyimininingwane yokuthi ipuleti liwumelela ngokwethembeka kangakanani lowo mqondo.

Ama-ion amabili anombala, hhayi amamolekyuli amabili

Ayikho kulezi zinto ezincibilikisiwe ehamba phakathi kwe-agar iyifomu eliphelele lefomula ephrintwe ebhodleleni. Zombili zingama-electrolyte anamandla ahlukana abe ama-ion emanzini.

I-potassium permanganate (KMnO4, imasi yefomula cishe engu-158.03 g/mol) ihlukana ibe ama-ion e-potassium nama-ion e-permanganate. Okuhambayo okunombala onsomi yi-ion ye-permanganate MnO4^-, enemasi cishe engu-118.94 g/mol, ezungezwe ungqimba lwamanzi. I-methylene blue chloride (usawoti ongenawo amanzi C16H18ClN3S, cishe ongu-319.85 g/mol) ihlukana ibe yi-chloride ne-cation ephilayo eluhlaza okwesibhakabhaka MB^+, enemasi cishe engu-284.41 g/mol, nayo ezungezwe amanzi. Irekhodi le-NIST le-methylene blue kanye nokufakwa kwe-methylene blue ku-ChEBI kubhala la mafomu, kanti umthombo ochaza ikhemistri nesakhiwo uchaza ukuthi kungani i-cation, usawoti ongenawo amanzi, nama-hydrate kudinga amagama ahlukene.

Kulokhu kuvela imiphumela emithathu.

Okokuqala, ukuqhathanisa u-158 no-320 kwenza umehluko wangempela wobukhulu phakathi kwama-ion anombala ubonakale umncane kunalokho oyikho, ngoba i-ion ensomi ecishe ibe ngu-119 g/mol incane kakhulu kune-cation eluhlaza okwesibhakabhaka ecishe ibe ngu-284 g/mol, futhi zombili ziphethe izingqimba zamanzi ezandisa ubukhulu bazo obusebenzayo.

Okwesibili, ama-cation e-methylene blue anamathela ezintweni. Akha ama-dimer namaqoqo amakhulu njengoba ukugxila kukhuphuka, futhi anamathela ebusweni be-agar; ukubopheka kwama-monomer nama-dimer kubikiwe ezifundweni zokunamathela ku-agar. Udayi onamathele awunyakazi. Ufaka umbala kujeli ngaphandle kokuhambisa umngcele.

Okwesithathu, impushana ye-reagent evamile iyi-hydrate, ngakho igremu elikaliwe liqukethe amanzi esakhiweni sekristalu. Ukuqhathaniswa kwe-trihydrate nefomu elingenawo amanzi kubonisa ukuthi lokho kuyishintsha kanjani i-molarity. Ukuze kuqhathaniswe ngokunobulungiswa ekilasini, lungisa izixazululo ezinosawoti abanokugxila okufanayo ngokwamamoli bese ubhala ukuthi kusetshenziswe liphi ifomu eliqinile.

Kungani imasi encane ingasho isivinini esikhulu lapha

Ezintweni eziwuketshezi ezinezixazululo ezinokugxila okuphansi, imodeli yokuqala engcono kunemasi yincazelo kaStokes-Einstein, lapho i-coefficient yokusabalala ilingana nezinga lokushisa elihlukaniswe nge-viscosity nerediyasi ye-hydrodynamic. Ubukhulu obuncane ngemva kokuzungezwa ngamanzi yibo obunikeza isivinini esikhulu. Imasi ephansi ivame ukuhlobana nobukhulu obuncane phakathi komndeni owodwa wamakhemikhali, ngakho imasi encane ingabonakala iyincazelo. Lokhu kuwukuhlobana, hhayi indlela le nqubo eyenzeka ngayo.

Umthetho kaGraham, othi isivinini sokuphuma kwegesi ngembobo encane silingana nokuphambana kwempande eyisikwele yemasi yemoli, awulawuli okwenzeka kuleli puleti. Ukususelwa kwawo kusekelwe emfundisweni yokunyakaza kwamagesi, efingqwe kule ncazelo ye-OpenStax yokuphuma nokusabalala kwamagesi. Uketshezi lwengeza ukumelana nokunyakaza ngenxa ye-viscosity, ukuzungezwa ngamanzi, imiphumela yokuma kwezinhlayiya, nokuminyana. Amajeli engeza isakhiwo sezimbotshana, ukusonteka kwemizila, ukunamathela ebusweni, nokusebenzelana kwamashaji ne-polymer.

Izinombolo ziveza umehluko. Umthetho kaGraham osetshenziswa ku-158 uma kuqhathaniswa no-320 ubikezela isilinganiso sezivinini esicishe sibe ngu-1.42. Ama-coefficient okusabalala akalwe emanzini ezixazululo ezinokugxila okuphansi aveza indaba ehlukile: i-permanganate isondele ku-1.6 kuya ku-1.8 × 10^-9 m^2/s, uma iqhathaniswa ne-methylene blue esondele ku-4.5 kuya ku-5 × 10^-10 m^2/s, okuyisilinganiso esisondele ku-3 noma ku-4. Imasi iyodwa ayikwazi ukuchaza leso silinganiso. Ubukhulu ngemva kokuzungezwa ngamanzi, ukwakheka kwamaqoqo, nokubopheka kujeli kuchaza ingxenye esele.

Thatha umqondo wokuthi imasi encane isho isivinini esikhulu njengemodeli enezimo ezicatshangwayo: izinhlayiya eziyindilinga, akukho ukubopheka, akukho ukwakheka kwamaqoqo, nezimo ezifanayo. Ipuleti alehlangabezani okungenani nezimbili zalezo zimo.

Indlela yokwenza ukuqhathanisa okunobulungiswa

Lokhu kuboniswa kwehluleka ngendlela isofthiwe eyehluleka ngayo: umqondo oyisisekelo ulungile, kodwa ukuwuguqulela esilinganisweni kugcwele izingibe. Ngayinye yalezi zinto ishintsha impendulo ngaphandle kokushintsha noma iyiphi impahla yamamolekyuli.

Sebenzisa iqoqo elilodwa le-agar elithelwe lajula ngokulinganayo, ithuluzi elilodwa lokusika imigodi, amavolumu oketshezi alinganayo, ukugxila okufanayo ngokwamamoli, nokugxila okuphansi ngokwanele ukukhawulela ukwakheka kwamaqoqo e-methylene blue nokugcina umbala ungagcwali kakhulu. Sika okungenani imigodi emithathu ephindaphinda ukuhlolwa kwento ngayinye encibilikisiwe, iqhelelane ukuze imingcele ingalokothi ihlangane. Mboza izitsha, uzigcine zivundlile, futhi ugcine izinga lokushisa lingaguquki, ngoba ucwaningo ngodayi ku-agar lubonisa ukuncika okukhulu ezingeni lokushisa nasekugxileni. Chaza isikhathi sokuqala njengomzuzu wokugcwalisa, bese uchaza umngcele ngaphambi kokulinganisa: umkhawulo ongaguquki wokubonakala kombala esithombeni ungcono kunomngcele ocatshangelwa ngamehlo, ngoba okuluhlaza okwesibhakabhaka nokunsomi kunemikhawulo ehlukene yokubonakala. Bhala ububanzi obubili obuphambana nge-engeli eqondile ebala ngalinye bese ukubuguqulela esilinganisweni serediyasi, ngoba ukudida irediyasi nobubanzi konakalisa noma iyiphi igrafu yesikwele sebanga ngokuphindwe kane.

Izichasiselo: iphaneli engakwesobunxele ibonisa irediyasi ekalwa uma kubukwa phezulu, kusukela onqenqemeni lomgodi kuya emngceleni wombala endaweni ngayinye esabalalayo; iphaneli engakwesokudla ibonisa isigaba esinqamulayo se-agar esinokujula komgodi nezindilinga zombala onciphayo njengoba uya ngaphandle; incazelo yezimpawu ibala izinto ezigcinwa zingaguquki (iphesenti le-agar, ukujiya, i-molarity kadayi, ivolumu, ubukhulu bomgodi, izinga lokushisa, isikhathi sokuqala, ukukhanyiswa).

Qaphela izinto ezilingisa ukusabalala. Uketshezi oluchithekela phezu kwe-agar lubukeka njengokusabalala okusheshayo, futhi lokhu kubhalwe njengomphumela ophambukisayo wemigodi emincane ye-agar. I-permanganate iyinto enamandla yokwenza i-oxidation futhi ingasetshenziswa iphele ngenxa yezinsalela ezincane zezinto eziphilayo, okwenza umngcele wayo ume noma ulahlekelwe umbala. I-methylene blue iyasebenza ezinqubweni ze-redox futhi ingafiphala ngaphansi kokukhanya noma ezimweni zokuncishiswa; ikhemistri ye-redox ye-methylene blue nefomu layo elincishisiwe elingenambala ichaza lokho kuziphatha.

Inothi elifushane ngesincibilikisi: yomibili imigodi ekubonisweni okuvamile isebenzisa izixazululo zamanzi. Uma inqubo ishintsha isincibilikisi, qala ngokubheka umhlahlandlela wokuncibilika nokulungiswa kwezixazululo, ngoba ukuncibilika nokwakheka kwamaqoqo kuyashintsha kuye ngesincibilikisi.

Ishidi lokubhala okubhekwa ekilasini

Kopisha leli thebula ezincwadini zokubhalela noma uphrinte umugqa owodwa ngomgodi ngamunye. Ithebula elilodwa ngesitsha ngasinye ligcina izilinganiso eziphindwayo zihlelekile futhi zithembekile.

Ukuze uhlaziye, dweba igrafu yesikwele sesilinganiso serediyasi uma siqhathaniswa nesikhathi esidlulile emgodini ngamunye, bese uqhathanisa ukuthambekela kwemigqa, ubhale nencazelo yomngcele eduze kwegrafu. Uma yonke imigqa eyisithupha iboniswa kanye nokuhlukahluka kwayo, ikilasi libona ukuhlukahluka njengedatha kunokuba likubone njengento ebangela amahloni.

Ukuphepha kuyingxenye yenqubo: gqoka amagilavu nokuvikela amehlo, ngoba i-methylene blue ishiya amabala esikhumbeni nasezingutsheni, kanti i-permanganate iyinto eyenza i-oxidation, eshiya amabala futhi ebangela ukucasuka. Ungafaki izixazululo emlonyeni, sebenzela phezu kwethreyi, futhi ulahle amapuleti noketshezi ngendlela yesikole yokulahla imfucuza yamakhemikhali kunokuba ukuthele kusinki.

Umusho okufanele ubhalwe

Ngaphansi kwalezi zimo ze-agar, zokugxila, nezinga lokushisa, umngcele obonakalayo we-permanganate uvame ukusabalala ngokushesha kunomngcele we-methylene blue. Lokhu kuhambisana nokuthi i-permanganate ine-coefficient yokusabalala esebenzayo enkulu, ikakhulu ngoba i-ion yayo ezungezwe amanzi incane kakhulu futhi ayakhi amaqoqo noma ibopheke ku-agar ngendlela i-methylene blue eyenza ngayo. Imasi yamamolekyuli ihlobana nalowo mehluko wobukhulu lapha, kodwa imasi iyodwa ayinqumi izivinini zokusabalala oketshezini noma emajelini.

Ikilasi elibhala lowo musho selifunde izinto ezimbili: iqiniso ngama-ion amabili anemibala, kanye nomkhuba wokubuza ukuthi ukuboniswa kukala ini ngaphambi kokwethemba lokho okubonakala kukusho.