Ubushushu wesiseko - yintoni na le nto?

Sithetha ntoni na ke ubushushu wesiseko, ngokunjalo ukuchaza iimeko ekuthiwa umgangatho. Ukuze alungise lo mba, ukufumana umahluko phakathi kwezinto alula nanzima. Ukuqinisa ingqikelelo "ubushushu wesiseko", cinga inxaki imichiza ethile.

Le enthalpy standard of ukwakheka kwezinto

76 kJ amandla yakhululwa indlela carbon ukuxhumana hydrogen. Kulo mzekelo, inani - na isiphumo wobushushu of yokusabela chemical. Kodwa le nobushushu ukubunjwa iimolekyuli methane evela izinto ezilula. "Kutheni?" - ubuze. Oku kungenxa yokuba izakhi ukuqala ezi yekhabhoni hydrogen. 76 kJ / Mol na amandla yaziwa ngokuba "ubushushu wesiseko".

Sheets data

Xa uluhlu zikhona iitafile ezininzi, eziquka ubushushu ukuyilwa ezahlukeneyo imichiza evela izinto ezilula. Umzekelo, ubushushu lokusekwa iziyobisi, indlela apho Co ₂ zikarhulumente sukube unalo isafobe 393,5 kJ / Mol.

ukubaluleka practical

Kutheni amanani data? Ubushushu wesiseko - ixabiso, esetyenziswa ngethuba ekubaleni isiphumo thermal nayiphi imichiza. Ukuze baqhube izibalo ezinje ifuna ukusetyenziswa umthetho uluhlu.

uluhlu lwamaxabiso

It is a umthetho esisiseko oluchaza iinkqubo amandla iqatshelwe kwikhosi yokusabela chemical. Ngexesha intsebenziswano waphawula utshintsho ubunjani kwinkqubo baphendule. Ezinye izinto iphela, amacandelo amatsha kuvela kwindawo yazo. Le nkqubo kunye notshintsho eneji lwangaphakathi nkqubo, oko kuboniswa ngokohlobo lomsebenzi okanye ubushushu. Lo msebenzi, nto leyo ehambisana kunye ukwandiswa; kuba ekudibaneni kwemichiza lelona nani lisezantsi. Ubushushu yakhululwa ukuguquka icandelo ukuya kwenye iziyobisi kusenokuba ixabiso elikhulu.

Xa siqwalasela iindidi utshintshwano, phantse zonke kukho nokufunxwa okanye ukukhululwa isixa esithile ubushushu. uluhlu - icandelo elikhethekileyo sele yenziwe kuba ingcaciso nesenzeko.

UMthetho Hess kaThixo

Ngenxa umthetho wokuqala obizwa, kwaba lula ukuphumeza lo ekubaleni isiphumo thermal ngokuxhomekeke kwiimeko basabela njani kwemichiza. izibalo Ngokusekelwe umthetho uluhlu engundoqo, ezizezi umthetho Hess. Vumela kuqulunqo yayo: thermal isiphumo imichiza yenguqu enxulumene uhlobo, isimo sokuqala nesokugqibela umbandela, ukuba sinxulumana indlela yentsebenziswano.

Yintoni lulandelayo ngcamango? Kwimeko imveliso ethile mfuneko kusetyenziswa kuphela omnye abe ngumfuziselo yentsebenziswano, basabela mazenziwe ngeendlela ezahlukahlukeneyo. Xa nawuphi na umcimbi, kungakhathaliseki ukuba ukunika indlela umbandela ofunekayo, isiphumo wobushushu le nkqubo iya kuhlala ixabiso ingatshintshwanga. Ukuchaza kuyimfuneko ukuba bashwankathele iziphumo wobushushu le zinguquko eziphakathi. Ngenxa umthetho Hess waba kungenzeka ukuba afeze izibalo izixa yeziphumo thermal, akunakwenzeka ukuba enze kwi calorimeter. Umzekelo, ukuba ubungakanani ubushushu ukuyilwa kwezinto carbon monoxide ibalwe umthetho Hess kaThixo, kodwa abantu balinge zesiqhelo ukufumanisa oko akuyi kuphumelela. Ngako oko iitheyibhile ezizodwa ngoko kubalulekile thermochemical apho amaxabiso lwamanani ezidwelisiweyo izinto ezahlukeneyo njengoko kuchaziwe phantsi kweemeko eziqhelekileyo

iingongoma ezibalulekileyo ekubaleni

Sisazi ukuba ubushushu wesiseko - ke ebushushwini yendlela, kwaye okubaluleke kakhulu imeko leempawu iyeza umbuzo. Ngokomzekelo, xa imilinganiselo ukuthatha ithathwa ukuba ibe kwimeko eqhelekileyo le carbon grafayithi, endaweni diamond. Kwakhona uthathe ingqalelo kwengcinezelo ubushushu, oko kukuthi, iimeko apho ekuqaleni baphendule amacandelo. Ezi eziphathekayo bayakwazi ukuba babe negunya nefuthe elibonakalayo indlela, uyandiswa okanye lincitshiswe umlinganiselo wamandla. Ukuze ukwenza izibalo ezisisiseko uluhlu wagqiba ukusebenzisa izalathisi obubambekayo kwengcinezelo obushushu.

nemiqathango yomgangatho

Ngokuba ukuvutha ukuyilwa mba - ukuzimisela isiphumo amandla ke kwiimeko eziqhelekileyo, ukwahlula ngokwahlukeneyo. Lobushushu okhethiweyo kuba ukubala 298K (degrees 25 C) Ingcinezelo - 1 emoyeni. Ukongeza, kukho ingongoma ebalulekileyo, nto kubalulekile ukunikela ingqalelo kukuba ubushushu ukubunjwa ukuba naziphi na izinto ezilula ngu zero. Oku kusengqiqweni, kuba izinto ezilula aziyo bona, oko kukuthi, akukho ukusetyenziswa amandla ngenxa kwazo.

semvelo uluhlu lwamaxabiso

Eli candelo of chemistry mihla linentsingiselo ekhethekileyo, ngenxa yokuba iziphumo kusetyenziswa isizukulwana amandla thermal apha kwenziwe izibalo ezibalulekileyo. Xa uluhlu, kukho amagama amaninzi kunye iingqiqo kubalulekile ukusebenza ukufumana iziphumo ezinqwenelekayo. Le enthalpy (? H) lubonisa ukuba indlela wemichiza senzeka kwinkqubo evaliweyo, kwakungekho ukusebenza impendulo esuka kwezinye reactants, uxinzelelo kwaba njalo. Le ukucaciswa ikuvumela ukuba uthethe malunga nokuchaneka izibalo eyenziwa.

Kuxhomekeka kuhlobo yokusabela ingqalelo, ubukhulu kunye umqondiso kwisiphumo se isiphumo thermal ungahluka kakhulu. Ngoko ke, ngokuba bonke inguquko ezibandakanya yokubola kwezinto ezimbaxa zibe kumacandelo eziliqela elula, izakuthatwa ukufunxeka bubushushu. Dibanisa nobuninzi yokusabela ukuqala imathiriyeli kwimveliso ngxuba sikhatshwe ukukhutshwa iimali ezinkulu amandla.

isiphelo

Ekucombululeni nayiphi na ingxaki thermochemical ukusebenzisa algorithm efanayo yezenzo. Okokuqala, le theyibhile imiselwa ecandelo kuqalwa ngasinye, kwakunye iimveliso abasabela ubungakanani ubushushu wesiseko, singalibalanga urhulumente aggregate. Okulandelayo, abaxhobileyo umthetho Hess ufanisa ukumisela ubuninzi ezingaziwayo.

ingqalelo ekhethekileyo kufuneka ihlawulwe kwi-akhawunti imiba stereochemical ekhoyo phambi kokuba into lokuqala okanye lokugqibela i'quadratic ethile. Ukuba abasabela ngayo izinto ezilula, ebushushwini babo umgangatho Ukwakheka ilingana zero, ngamanye amazwi, loo amacandelo kuba nafuthe result afunyenwe izibalo. Zama ukusebenzisa ulwazi basabela ethile. Ukuba umzekelo njengoko inkqubo ukubunjwa oxide yentsimbi (Fe ³⁺⁾ metal engcwengekileyo zakudibana le mifanekiso, ixabiso reference inokufumaneka ebanjwe umgangatho ukubunjwa. Kuba oxide yentsimbi (Fe ³⁺⁾ kuya kuba -822,1 kJ / Mol le mifanekiso (iziyobisi ezilula) ngu zero. Indlela abasabela ngenxa ivelisa carbon monoxide (CO), apho isalathisi has ixabiso - 110,5 kJ / Mol, lo gama ubushushu ukubunjwa wakhupha intsimbi ingqamana zero. Ukurekhoda ebanjwe umgangatho ukuyilwa kwalo intsebenziswano wemichiza luphawulwa ngolu hlobo lulandelayo:

_Malunga 298 H = 3 × (-110,5) -? (-822,1) = -331,5 + 822,1 = 490,6 kJ.

Ukuhlalutya wafumana umthetho Hess japan amanani, unako ukwenza kwisigqibo esisengqiqweni sokuba inkqubo i ukuguqulwa endothermic, ngamanye amazwi oko kuthatha zatrachivaniya lokunciphisa amandla yentsimbi indlela oxide yayo ferric.