Yiyiphi impembelelo yomshushu yokuphendula

Nangona ukuqhelana negama elithi "impembelelo yefuthe yempendulo yamakhemikhali" kwininzi kwenzeka kwizifundo zekhemistry, kodwa kusetyenziswa ngokubanzi. Kunzima ukuyicinga nayiphi na indawo yomsebenzi apho le nto ingasetyenziswanga.

Makhe sibone umzekelo wabanye babo, apho kuyimfuneko ukwazi ukuba yintoni impembelelo yefuthe yempendulo. Okwangoku, imboni yezimoto ikhula ngezinga elimangalisayo: inani leemoto ngonyaka liyakwandisa amaxesha amaninzi. Ngexesha elifanayo, umthombo oyintloko wamandla kubo ngepetroliyo (ukuyila okunye ukufumana ukuziphatha kwabo kuphela kwiitotype ezinye). Ukulungisa amandla okubasa amafutha, izongezo ezizodwa zisetyenziselwa ukunciphisa ubunzulu bokukhunjulwa. Umzekelo ocacileyo yi-monomethylaniline. Xa kufunyenwe, umphumo we-thermal we-reaction uyabalwa, okweli candelo -11-19 kJ / mol.

Enye intsimi yesicelo yoshishino lokutya. Ngokuqinisekileyo, nayiphi na umntu oyalele ingqalelo kwimixholo yekharikhi yemveliso ethile. Kule meko, inani le-caloric kunye nempembelelo ye-thermal yempendulo ihambelana ngokuthe ngqo, kuba ngexesha lokukhutshwa kokushisa kokutya kukhishwa. Ukulungisa ukutya kwakho kusekelwe kule datha, unokufikelela ekunciphiseni okunzima komzimba. Nangona into yokuba impembelelo yefuthe yempendulo iyalinganiswa kuma-joules, kukho ubudlelwane ngqo phakathi kwabo kunye neekhalori: 4 J = 1 kcal. Imveliso yokutya, inani eliqikelelwayo (ubunzima) lidlalwa.

Makhe sibuyele kulo mbono kwaye sinike inkcazo. Ngoko, ukushisa kwesibonakaliso kubonisa inani lokushisa okukhululwe okanye ukuxutywa yinkqubo xa iinkqubo zeekhemikhali zivela kuyo . Kufuneka kukhunjulwe ingqalelo ukuba ngaphezu kokushushu, i-radiation ingenziwa. Impembelelo ye-thermal yokusabela kwamakhemikhali ibalwa ngokulinganayo kumlinganiselo phakathi kwamanqanaba emandla kwenkqubo: yokuqala kunye nentshonalanga. Ukuba kwindlela yokufudumala ukushisa kuthathwa kwiindawo ezizungezile, kuthethwa inkqubo yokugqibela. Ngako oko, ukukhululwa kwamandla ashushu kuluphawu lwesenzo esibuhlungu. Ziyinto elula ukuhlula: ukuba ixabiso lemali yamandla ekhutshwe ngenxa yempendulo yenziwa ibe mkhulu kuneleyo esetyenziselwe yona (umzekelo, amandla omshushu omoya ovuthayo), ke oku kuphazamiseka. Kodwa ngenxa yokuqhekeka kwamanzi kunye namalahle kwi-hydrogen kunye ne- carbon monoxide, kuyimfuneko ukuchitha amandla angakumbi ekufudumezeni, ngoko ukutshatyalaliswa kwawo (endothermy) kwenzeka.

Impembelelo ye-thermal yokusabela ingabalwa ngokusebenzisa amafomula awaziwayo. Ekubaleni, umphumo we-thermal uchazwe ngetekisi Q (okanye i-DH). Ukwahluke kwindlela yohlobo (endo okanye exo), ngoko Q = - DH. Ukulingana kwe-Thermochemical kuthatha inkcazo yempembelelo yefuthe kunye neempembelelo (ukuchaneka nokulungisa ukubala). Ubungqina bezo zilinganiso kukuba kunokwenzeka ukutshintsha ubukhulu bemiphumo yefuthe kunye nezinto ngokwazo kwiindawo ezahlukeneyo. Kuyakwazi ukwenza ukukhutshwa kwexesha ngekota okanye ukongezwa kweefomula ngokwabo, kodwa kuthethwa ngolu hlobo lwezinto ezikhoyo.

Makhe sibone umzekelo wokutshisa i-methan, i- carbon, i-hydrogen:

1) CH4 + 2O2 = CO2 + 2H2O + 890 kJ

2) C + O2 = CO2 + 394 kJ

3) 2H2 + O2 = 2H2O + 572 kJ

Ngoku sithatha i-2 ne-3 ukusuka kwi-1 (kumacala angakwesokunene ukusuka ngakwesokudla, ngakwesobunxele-ukusuka kwesobunxele).

Ngenxa yoko, sifumana:

CH4 - C - 2 H4 = 890 - 394 - 572 = - 76 kJ.

Ukuba zonke iinxalenye zanda nge-1 (susa ixabiso elibi), ngoko siyafumana:

C + 2H2 = CH4 + 76 kJ / mol.

Ungayichaza njani umphumo? Impembelelo ye-thermal eyenzekayo xa i-methane iqulunqwe ukusuka kwi-hydrogen ne-carbon i-76 J nganye kwi-mole ye-gas eyenziweyo. Kwakhona kulandela kwiifomula eziza kukhishwa amandla ombane , oko kukuthi, yinkqubo ephazamisayo. Ezi zibalo zenza ukuba kunokwenzeka ukuba ugweme imfuno yecandelo lezonyango ezizodwa, ezihlala zibandakanya ubunzima.