Kuzo zombili i-physics kanye ne-chemistry umqondo usetshenziselwa ukukala amandla aqukethwe emzimbeni. Sikhuluma nge enthalpy. Luhlobo lwesilinganiso olukhombisa inani lamandla aqukethwe emzimbeni noma ohlelweni olunomthamo othile, ongaphansi kwengcindezi futhi ongashintshaniswa nemvelo. I-enthalpy yesistimu imelwe uhlamvu H kanye neyunithi yomzimba ehlotshaniswa nayo ukukhombisa amanani wamandla yiJoule.
Kulesi sihloko sizokutshela zonke 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 zifundazwe zingaba namandla, zibe uketshezi noma zibe negesi noma kube nesixazululo. Isimo se-allotropic yisimo esizinzile kunazo zonke. Isibonelo, isimo se-allotropic esizinzile kunayo yonke i-carbon i-graphite, ngaphezu kokuba ngaphansi kwezimo ezijwayelekile lapho amanani okucindezeleka ekhona 1 umkhathi nokushisa kungama-degree angama-25.
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 okuxakayo, ama-reactants kumele abe namandla aphezulu kunemikhiqizo. Ngokuphambene nalokho, ukuze kwenzeke ukusabela kokuphela komzimba ama-reactants kumele abe namandla amancane kunemikhiqizo. Ukuze i-equation yamakhemikhali yakho konke lokhu ibhalwe kahle, kuyadingeka ukuthobela umthetho wokongiwa kwendaba. Lokho wukuthi, i-equation yamakhemikhali kufanele iqukathe imininingwane ngesimo somzimba se-reactants nemikhiqizo. Lokhu kwaziwa njengombuso wokuhlanganisa
Futhi khumbula ukuthi Izinto ezimsulwa zine-enthalpy yokwakheka okulingana no-zero. Lawa mavelu enthalpy atholakala ngaphansi kwezimo ezijwayelekile, njengalezo ezibalulwe ngenhla, nangendlela ezinze ngayo. Kuhlelo lwamakhemikhali lapho kukhona ama-reactants nemikhiqizo, i-enthalpy yokuphendula ilingana ne-enthalpy yokwakheka ngaphansi kwezimo ezijwayelekile.
Siyazi ukuthi i-enthalpy yamanani wokwakheka kwamakhemikhali amakhemikhali athile angaphili futhi angokwemvelo asungulwa ezimeni ze-1 atmosphere yengcindezi nama-degree angama-25 okushisa.
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 yomqeqeshi ifunwa, ihlala noma ithola kokubili ama-reagents nemikhiqizo. Esinye sezici okufanele sigcwaliseke ukubala i-enthalpy yokuphendula ukuthi ukusabela uqobo kumele kwenzeke ngokucindezela njalo. Ngamanye amagama, kuso sonke isikhathi esithathayo ukuze ukwenzeka kwamakhemikhali kwenzeke, ingcindezi kufanele igcinwe njalo.
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 akulutho ngaphandle kwezinqubo ezahlukahlukene ze-thermodynamic ezenzeka ngengcindezi ethile. Amanani wokucindezela avame kakhulu anikezwa ngaphansi kwezimo ezijwayelekile zengcindezi yasemkhathini. Ngakho-ke, zonke izinqubo ze-thermodynamic ezenzeka ngale ndlela zibizwa nge-isobaric, ngoba kwenzeka ngokuxineka 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 esake sakhuluma ngakho ngaphambili, i-enthalpy ngumsebenzi wombuso. Lapho sibala ushintsho lwe-enthalpy, empeleni sibala umehluko wemisebenzi emibili. Le misebenzi ivame ukuncika kuphela esimweni sohlelo. Lesi simo sohlelo siyahlukahluka ngokuya ngamandla angaphakathi nevolumu yohlelo uqobo. Njengoba sazi ukuthi inguqulo ihlala ingaguquguquki kukho konke 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.