Kuzo zombili i-physics kanye ne-chemistry umqondo usetshenziselwa ukukala amandla aqukethwe emzimbeni. Sikhuluma nge enthalpy. Kuwuhlobo lokulinganisa olusitshela inani lamandla aqukethwe emzimbeni noma ohlelweni olunomthamo othile, olungaphansi kwengcindezi, futhi olungashintshwa nendawo ezungezile. I-enthalpy yohlelo imelelwa uhlamvu H futhi iyunithi yomzimba ehlotshaniswa nayo ukukhombisa amanani wamandla yiJoule.
Kulesi sihloko sizokutshela konke izici nokubaluleka kwe-enthalpy.
Izici eziyinhloko
Singasho ukuthi i-enthalpy ilingana namandla angaphakathi lapho uhlelo lukhona kanye nezikhathi zengcindezi ivolumu yohlelo olufanayo. Lapho sibona ukuthi amandla ohlelo, ingcindezi nevolumu kuyimisebenzi yombuso, i-enthalpy nayo. Lokhu kusho ukuthi, lapho isikhathi sifika, singenzeka ezimeni ezithile zokugcina zokugcina ukuze okuguquguqukayo kusize ukutadisha lonke uhlelo luphelele.
Into yokuqala ukwazi ukuthi yini i-enthalpy yokwakheka. Imayelana ne- ukushisa okumuncwe okukhohliwe uhlelo lapho imole engu-1 yento yomkhiqizo ikhiqizwa ezintweni ezisesimweni esijwayelekile. Lezi zifunda zingaba ziqinile, zibe uketshezi noma zibe negesi noma kwezinye izimo zibe yisixazululo. Isimo se-allotropic yisimo esizinzile kakhulu. Isibonelo, isimo se-allotropic esizinzile kunazo zonke yi-graphite, futhi sitholakala ngaphansi kwezimo ezivamile lapho amanani okucindezela ekhona. 1 umkhathi nokushisa kungama-degree angama-25. Ukubaluleka kokwazi i-enthalpy kubalulekile ekuqondeni amandla ahilelekile ekuphenduleni kwamakhemikhali okuhlukahlukene, kanye nokuhlaziya imithelela yamagagasi okushisa.
Sigcizelela ukuthi izinhlaka zokwakheka ngokwalokho esikuchazile zenzelwe imvukuzane engu-1 eyakhiwe. Ngale ndlela, ngokuya ngenani lemikhiqizo ekhona esetshenziswayo, ukuphendula kuzofanela kulungiswe ngama-coefficients ayiqhezu.
Ukwakheka enthalpy
Siyazi ukuthi kunoma iyiphi inqubo yamakhemikhali, i-enthalpy yokwakheka ingaba okuhle nokubi. Le enthalpy inhle lapho ukusabela kuphelile. Ukuthi ukusabela kwamakhemikhali kuphele amandla kusho ukuthi kungamunca ukushisa kwaphakathi nendawo. Ngokwesinye isandla, sine-enthalpy engemihle lapho ukusabela kukhathaza. Ukuthi ukusabela kwamakhemikhali kuyaphazamisa kusho ukuthi kukhipha ukushisa kusuka ohlelweni kuye ngaphandle.
Ukuze kwenzeke ukusabela kwe-exothermic, ama-reactants kufanele abe namandla amakhulu kunemikhiqizo. Ngokuphambene nalokho, ukuze i-endothermic reaction yenzeke ama-reactants kufanele abe namandla amancane kunemikhiqizo. Ukuze i-chemical equation ukuze konke lokhu kubhalwe ngendlela efanele, umthetho wokongiwa kwezinto kufanele ugcwaliseke. Okusho ukuthi, isibalo samakhemikhali kufanele siqukathe ulwazi mayelana nesimo somzimba sama-reactants kanye nemikhiqizo, okuwukhiye ocwaningweni lwe-.
Futhi khumbula ukuthi Izinto ezimsulwa zine-enthalpy yokwakheka okulingana no-zero. Lezi zindinganiso ze-enthalpy zitholakala ngaphansi kwezimo ezijwayelekile, njengoba sishilo ngenhla, futhi ngendlela yazo ezinzile kakhulu. Kuhlelo lwamakhemikhali lapho ama-reactants kanye nemikhiqizo ikhona, i-enthalpy yokusabela ilingana ne-enthalpy yokwakheka ngaphansi kwezimo ezijwayelekile.
Enthalpy yokusabela
Sesivele sishilo ukuthi yini i-enthalpy yokwakheka. Manje sizochaza ukuthi yini i-enthalpy of reaction. Kungumsebenzi we-thermodynamic osiza uku bala ukushisa okutholakele noma ukushisa okulethwe ngesikhathi sokuphendula kwamakhemikhali. Ibhalansi ifunwa ekushintshisaneni kokushisa kwakho kokubili ama-reactants kanye nemikhiqizo. Esinye sezici okufanele kuhlangatshezwane nazo ukuze kubalwe i-enthalpy yokusabela ukuthi ukusabela ngokwayo kufanele kwenzeke ngokucindezela njalo. Okusho ukuthi, kuso sonke isikhathi esithathayo ukuze kwenzeke ukusabela kwamakhemikhali, ukucindezela kufanele kuhlale kumanani angashintshi.
Siyazi ukuthi i-enthalpy inezilinganiso zamandla yingakho ilinganiswa kuma-joules. Ukuqonda ubudlelwane be-enthalpy ekushiseni okushintshaniswa ngesikhathi sokuphendula kwamakhemikhali kubalulekile ukuya emthethweni wokuqala we-thermodynamics. Futhi ukuthi lo mthetho wokuqala usitshela ukuthi ukushisa okushintshaniswa ngenqubo ye-thermodynamic kuyalingana nokwehluka kwamandla angaphakathi ento noma izinto ezibandakanyeka enqubeni kanye nomsebenzi owenziwe yizinto ezishiwoyo ngesikhathi senqubo.
Siyazi ukuthi konke ukusabela kwamakhemikhali akuyona into engaphezu kwezinqubo ezihlukahlukene ze-thermodynamic ezenzeka ngengcindezi ethile. Amanani okucindezela avame kakhulu anikezwa ngaphansi kwezimo ezijwayelekile zokucindezela komkhathi. Ngakho-ke, zonke izinqubo ze-thermodynamic ezenzeka ngale ndlela zibizwa ngokuthi i-isobaric, ngoba zenzeka ngokucindezela njalo.
Kuyinto evamile ukubiza ukushisa kwe-enthalpy. Kodwa-ke, kufanele kucace ukuthi ayifani nokushisa, kepha ukushintshana ngokushisa. Okusho ukuthi, akukhona ukushisa okungafundisa isifundo noma ukushisa kwangaphakathi ama-reactants nemikhiqizo abanayo. Kuyinto ukushisa okushintshaniswa kuyo yonke inqubo yokusabela kwamakhemikhali.
Ubudlelwano nokushisa
Ngokungafani nalokho esikuxoxile ngaphambili, i-enthalpy iwumsebenzi wombuso. Uma sibala ushintsho lwe-enthalpy, sibala ngempela umehluko wemisebenzi emibili. Le misebenzi ivamise ukuncika ngokukhethekile esimweni sohlelo. Lesi simo sesistimu siyahlukahluka kuye ngamandla angaphakathi kanye nevolumu yesistimu ngokwayo. Njengoba sazi ukuthi inguqulo ihlala ingashintshi kulo lonke ukusabela kwamakhemikhali, i-enthalpy yokuphendula ayikho ngaphezu komsebenzi wombuso oncike kumandla angaphakathi nevolumu.
Ngakho-ke, singachaza i-enthalpy yama-reactants ekuphenduleni kwamakhemikhali njengenani ngalinye lawo. Ngakolunye uhlangothi, sichaza into efanayo kepha kwimikhiqizo njengesamba se-enthalpy yayo yonke imikhiqizo.
Ngiyethemba ukuthi ngalolu lwazi ungafunda kabanzi nge-enthalpy nezici zayo.