Umphumela Wokushisa Esilinganisweni Sokusabela
I-Pendahuluan
Ukusabela kwamakhemikhali kuyinqubo lapho into eyodwa noma ngaphezulu (ama-reactant) iguqulwa ibe yinto eyodwa noma ngaphezulu (imikhiqizo). Le nqubo ihilela izinguquko zamandla kanye nokuhlela kabusha kwezibopho zamakhemikhali. Esinye sezici eziyinhloko ezithinta izinga lokusabela kwamakhemikhali izinga lokushisa. Ukuqonda ukuthi izinga lokushisa lithinta kanjani amazinga okusabela kubalulekile emikhakheni efana nemboni yamakhemikhali, i-biochemistry, kanye nesayensi yezemvelo.
Izinga lokusabela lilinganisa ukuthi ama-reactant adliwa ngokushesha kangakanani noma imikhiqizo yakheka kanjani ngesikhathi sokusabela kwamakhemikhali. Ukusabela okusheshayo kuvame ukufiseleka embonini ukwandisa ukusebenza kahle kanye nokukhiqiza. Kodwa-ke, kwezinye izimo, ukulawulwa okuqinile kwamazinga okusabela kuyadingeka ukuqinisekisa ukuphepha komkhiqizo kanye nekhwalithi. Lesi sihloko sizoxoxa ngezimiso eziyisisekelo zendlela izinga lokushisa elithinta ngayo amazinga okusabela, kusetshenziswa i-kinetics yamakhemikhali kanye nomqondo wamandla okusebenza.
Ithiyori ye-Chemical Kinetic
Ithiyori ye-kinetic yamakhemikhali inikeza indlela yokuqonda ubudlelwano phakathi kwezinga lokushisa kanye nezinga lokusabela. Kunezinhlobo ezimbili eziyinhloko ezichaza lobu budlelwano: ithiyori yokushayisana kanye nethiyori yesimo sokuguquka.
Ithiyori Yokungqubuzana
Ngokusho kwethiyori yokushayisana, ukusabela kwamakhemikhali kwenzeka lapho ama-molecule e-reactant eshayisana namandla anele futhi eqonde ngqo ukuze awele isithiyo samandla esaziwa ngokuthi amandla okusebenza. Amandla okusebenza yiwona amandla amancane adingekayo ukuqala ukusabela.
I-Arrhenius equation ichaza ubudlelwano phakathi kwesilinganiso sokusabela kanye nokushisa, lapho \( k \) kuyisilinganiso esingaguquki, \( A \) kuyisici semvamisa noma isici sangaphambi kokubonisa esihlobene nenani eliphelele lokushayisana okuphumelelayo, \( E_a \) amandla okusebenza, \( R \) iyisilinganiso segesi esijwayelekile, kanye \( T \) kuyisilinganiso sokushisa ku-Kelvin.
\[ k = A \exp{\left(\frac{-E_a}{RT}\right)} \]
Kusukela kulesi sibalo, kungabonakala ukuthi izinga lokusabela liyakhula ngokushisa okwandayo, ngoba izinga lokushisa elikhulayo lizokwandisa amandla e-kinetic ama-molecule, okubangela ukushayisana okuphumelelayo okunamandla anele ukudlula amandla okusebenza.
Ithiyori Yesimo Sokuguquka
Ithiyori yesimo sokuguquka inikeza umbono ohlukile ogxile ekwakhekeni nasekuqhekekeni kwama-complexes asebenzayo axhumanisa ama-reactants nemikhiqizo. Ngokwalo mbono, ama-molecule asabelayo akha ama-complexes esimo sokuguquka kwesikhashana abese ehlangana ukuze akhe imikhiqizo. Amandla adingekayo ukwakha la ma-complexes yi-activation energy.
Njengasembonweni wokungqubuzana, umbono wesimo sokuguquka uphinde ubikezele ukuthi izinga lokushisa elikhulayo landisa amazinga okusabela. Lokhu kungenxa yokuthi amazinga okushisa aphezulu anikeza amandla engeziwe okwakhiwa kwezindawo eziyinkimbinkimbi zesimo sokuguquka.
Umphumela Wokushisa Ezinhlotsheni Ezihlukahlukene Zokusabela
Umphumela wokushisa esilinganisweni sokusabela ungahluka kuye ngohlobo lokusabela kwamakhemikhali. Nazi ezinye izibonelo:
Ukusabela Okungavamile kanye Nokungapheli
– Ukusabela Okungaphandle: Ukusabela okukhipha ukushisa endaweni ezungezile. Ngenkathi izinga lokusabela livame ukwanda njengoba izinga lokushisa likhuphuka, endaweni ethile, amazinga okushisa aphezulu kakhulu anganciphisa izinga lokusabela ngoba ukuguquka kokusabela kuba lula.
– Ukusabela Kwe-Endothermic: Ukusabela okumunca ukushisa okuvela endaweni ezungezile. Ukwandisa izinga lokushisa kusebenza kangcono ekwandiseni izinga lalokhu kusabela ngoba amandla engeziwe enza kube lula ukwakheka kwemikhiqizo evela kuma-reactants.
Ukusabela Okufanayo Nokungafani
– Ukusabela Okufanayo: Zonke izinto ezisabelayo zisesigabeni esisodwa (igesi noma uketshezi). Ukwandisa izinga lokushisa kuphumela ekwandeni kwamandla e-kinetic ezinhlayiya, ngaleyo ndlela kwandisa imvamisa namandla okushayisana phakathi kwezinhlayiya.
– Ukusabela Okungajwayelekile: Ukusabela kuhilela ama-reactant ezigabeni ezahlukene (isb., okuqinile kanye negesi). Ukwandisa izinga lokushisa kuvame ukwandisa izinga lokusabalala kanye nokusebenzisana phakathi kwezigaba, ngoba izinhlayiya zisebenza kakhulu ekuhambeni phakathi kwezigaba ezahlukene.
Umphumela Wezinga Lokushisa Emisebenzini Yezimboni
Ukuqonda ukuthi izinga lokushisa lithinta kanjani amazinga okusabela kubalulekile embonini yamakhemikhali. Nazi ezinye izindlela ezisebenzayo:
Imboni Yokukhiqiza
Ekukhiqizeni amakhemikhali, ukukhulisa izinga lokushisa kuvame ukusetshenziselwa ukusheshisa ukusabela nokwandisa ukukhiqizwa ngesikhathi esifushane. Esinye isibonelo ukwelashwa kokushisa ukuthuthukisa izakhiwo ezithile emikhiqizweni ye-polymer noma ezinye izinto ezidinga ukulawulwa kwezinga lokushisa ngesikhathi senqubo yokusabela.
Imboni Yezemithi
Ekuhlanganisweni kwezidakamizwa, ukulawulwa kokushisa kuyisihluthulelo sokufeza ukusebenza kahle kokusabela okuphezulu ngaphandle kokubeka engcupheni ikhwalithi yomkhiqizo. Ukushintshashintsha kokushisa okungafuneki kungaholela ekwakhekeni kwemikhiqizo engaba yingozi.
I-Biotechnology
Ukusabela kwamakhemikhali e-biochemical okubandakanya ama-enzyme kuzwela kakhulu ekushiseni. I-enzyme ngayinye inokushisa okuphezulu lapho umsebenzi wayo uphezulu khona. Ukuphambuka kulokhu kushisa okuphezulu kungabangela ukuguquka kwama-enzyme kanye nokwehla kwesilinganiso sokusabela. Ngakho-ke, ukuqonda imiphumela yokushisa kubalulekile ekuvuthweni nakwezinye izinqubo zokukhiqiza kwamakhemikhali.
Ucwaningo Lwesibonelo: Ukulawulwa Kokushisa Ekukhiqizweni Kwe-Sulfuric Acid
Ukukhiqizwa kwe-sulfuric acid kuyisibonelo esisodwa sendlela izinga lokushisa elithinta ngayo amazinga okusabela esikalini sezimboni. Inqubo yokuxhumana iyindlela evame kakhulu yezimboni yokukhiqizwa kwe-sulfuric acid. Le nqubo ihilela ukushisa i-sulfur emoyeni ukuze kukhiqizwe i-sulfur dioxide (SO₂), bese kufakwa i-oxidizing i-SO₂ nge-oxygen ukuze kwakhiwe i-sulfur trioxide (SO₃) kusetshenziswa i-vanadium pentoxide (V₂O₅) catalyst. Ekugcineni, i-SO₃ isabela namanzi ukuze ikhiqize i-sulfuric acid (H₂SO₄).
Isinyathelo esibalulekile kule nqubo ukujiya kwe-SO₂ kuya ku-SO₃. Lokhu kusabela ku-exothermic, futhi izinga lokushisa elifanele lokusebenza kwe-catalyst licishe libe ngu-400–450°C. Lapho izinga lokushisa liphansi kakhulu, izinga lokusabela lihamba kancane, kanti lapho izinga lokushisa liphezulu kakhulu, kungenzeka ukuthi i-catalyst icime futhi umkhiqizo unciphe ngenxa yobunzima bokulawula i-reaction kinetics kanye ne-thermodynamics.
Isiphetho
Umphumela wokushisa emazingeni okusabela uyisici esiyisisekelo se-kinetics yamakhemikhali, esisekela izinhlelo zokusebenza eziningi ezisebenzayo kuzo zonke izimboni ezahlukene. Kokubili i-collision theory kanye ne-transition state theory zichaza ukuthi ukwanda kokushisa ngokuvamile kusheshisa ukusabela ngokunciphisa izithiyo zamandla okusebenza kanye nokwandisa amandla e-kinetic ama-molecule. Ukusetshenziswa kwangempela kwalomqondo kudinga ukulawulwa kokushisa okucophelelayo ukuze kufezwe ukusebenza kahle kwenqubo kanye nokugcina ikhwalithi yomkhiqizo oyifunayo.
Lokhu kuqonda akusizi nje kuphela ososayensi nonjiniyela ekwakheni ukusabela kwamakhemikhali okusebenza kahle kodwa futhi kudlala indima ebalulekile ekusungulweni kwezobuchwepheshe nasekuthuthukiseni ukukhiqizwa kwezimboni jikelele.
