A zafi na samuwar - menene wannan?

Mun yi magana game da abin da yake cikin zãfi da samuwar, kazalika da ayyana yanayin da ake kira misali. Domin warware wannan batu, gano da bambance-bambance tsakanin sauki da hadaddun abubuwa. Don ƙarfafa manufar "zãfi samuwar", la'akari da takamaiman sinadaran lissafi.

A misali enthalpy na samuwar abubuwa

76 KJ na makamashi sake a dauki na carbon tare da hydrogen gas hulda. A wannan yanayin, da adadi - ne thermal sakamako na sinadaran dauki. Amma wannan zafin samuwar methane kwayoyin daga sauki abubuwa. "Me ya sa?" - Ka tambayi. Wannan shi ne saboda cewa da fara gyara su ne carbon da hydrogen. 76 KJ / mol ne makamashi da cewa chemists kira "zãfi samuwar".

data Sheets

A thermochemistry zama yawa alluna, wanda dauke zafin samuwar daban-daban sinadaran abubuwa daga sauki abubuwa. Alal misali, zafi na samuwar da abu, da dabara na wanda CO ₂ a cikin gaseous jihar yana wani adadi 393,5 KJ / mol.

m muhimmancin

Me ne data dabi'u? A zafi na samuwar - mai daraja, wanda aka yi amfani a lokacin da lissafi na thermal sakamako na wani tsarin sunadarai. Domin gudanar da wannan lissafin bukatar yin amfani da dokar thermochemistry.

thermochemistry

Yana da wani muhimman hakkokin dokar da ya bayyana samar da makamashi matakai lura a cikin shakka daga sunadarai dauki. A lokacin da hulda lura ingantaccen canje-canje a cikin maida martani tsarin. Wasu abubuwa bace, sabon gyara bayyana a inda suke. Wannan tsari ne tare da wani canji a cikin ciki makamashi na tsarin, an nuna a cikin wani nau'i na aiki ko kadan. The aiki, wanda ake dangantawa da tsawo, domin sinadaran halayen ne mafi ƙasƙanci adadi. A zafi saki a cikin hira da daya bangaren a cikin wani abu na iya zama mai girma darajar.

Idan muka yi la'akari da wani iri-iri-canje, kusan duk akwai sha ko saki wani adadin zafi. thermochemistry - musamman sashe da aka halitta da wani bayani na mamaki.

Hess ta Law

Saboda da farko ka'idar Thermodynamics, ya zama zai yiwu a gudanar da wani lissafi na thermal sakamako dangane da yanayin da sinadaran dauki. Bisa lissafin da a kan babban thermochemistry dokar, wato dokar Hess. Bari ta halitta: thermal sakamako sinadaran canji alaka da yanayi, da farko da kuma karshe Jihar littattafai, shi ba a hade tare da hanyar hulda.

Abin da ya bi daga wannan halitta? A cikin hali na wani takamaiman samfurin bukata ba za a yi amfani kawai da daya embodiment na hulda, da dauki iya za'ayi a hanyoyi daban-daban. A wani taron, ko ta yaya ka ba da ake so abu, da thermal sakamako daga cikin tsari zai kasance canzawa darajar. Don ayyana shi wajibi ne don takaita thermal effects na tsaka-tsaki canje. Saboda dokar Hess ya zama zai yiwu a gudanar da wani lissafin da yawa na thermal effects, ba shi yiwuwa a gudanar da wani a cikin calorimeter. Alal misali, don quantify zafin samuwar carbon monoxide abubuwa lasafta ta Hess da dokar ta, amma ta yau da kullum experimentation domin sanin shi za ka yi nasara ba. Saboda haka muhimmanci musamman thermochemical alluna a cikin abin da lamba dabi'u da aka jera for daban-daban abubuwa kamar yadda aka ayyana a karkashin tuta yanayi

Da muhimmanci da maki a cikin lissafi

Ganin cewa zafin samuwar - shi ne zafi na dauki, na musamman muhimmancin ne da tara jihar na da dũkiyõyinsu a tambaya. Alal misali, sa'ad da shan ma'aunai aka dauke su wani misali Jihar carbon graphite, maimakon lu'u-lu'u. Har ila yau, ya yi la'akari da irin matsin lamba da kuma yawan zafin jiki, da cewa shi ne, yanayin a cikin abin da aka farko da martani aka gyara. Wadannan jiki yawa ne iya exert gagarumin tasiri a kan dauki, ta ƙara ko rage adadin kuzari. Domin yin asali lissafin a thermochemistry yanke shawarar yin amfani kankare Manuniya na matsa lamba da kuma yawan zafin jiki.

misali yanayi

Saboda zafin samuwar al'amarin - a tabbatar da dalilin da sakamako na makamashi ne a misali yanayi, rarrabe su dabam. Zazzabi zaba domin lissafi na 298K (25 digiri centigrade) Matsa lamba - 1 yanayi. Bugu da kari, wani muhimmin batu, wanda yake shi ne daraja biya da hankali ga shi ne gaskiya cewa zafin samuwar ga wani sauki abubuwa ne sifili. Wannan shi ne ma'ana, saboda sauki abubuwa ba su hade kansu, cewa shi ne, akwai wani kuzari ga su aukuwa.

abubuwa na thermochemistry

Wannan sashe na zamani sunadarai yana da wani muhimmanci na musamman, domin shi ne a nan za'ayi muhimmanci lissafin suna da sakamakon amfani da thermal ikon tsara. A thermochemistry, akwai mutane da yawa sharuddan da Concepts da suke da muhimmanci ga aiki don samun ake so sakamakon. A enthalpy (? H) na nuna cewa wani sinadaran dauki dauki wuri a cikin rufaffiyar tsarin, akwai wani sakamako a kan mayar da martani daga sauran reactants, da matsa lamba da aka m. Wannan bayani ba ka damar magana game da daidaito da lissafin yi.

Dangane da abin da irin dauki yana dauke, da girma da kuma alamar da sakamakon thermal sakamako iya bambanta muhimmanci. Saboda haka, domin duk Abubuwan Taɗi shafe da bazuwar na hadaddun abubuwa cikin da dama sauki gyara, shi aka zaci zafi sha. Haxawa da wani jam'i na dauki fara kayan a wani hadadden samfurin tare da a saki gwaji yawa na makamashi.

ƙarshe

A warware wata matsala thermochemical tambaya guda algorithm na ayyuka. Da farko, a cikin tebur aka ƙaddara ga kowane fara bangaren, kazalika da dauki kayayyakin yawa zafi na samuwar, ba manta da tara jihar. Next, m Hess dokar daidaita domin sanin unknown yawa.

Musamman hankali ya kamata a biya zuwa lissafi stereochemical dalilai data kasance kafin na farko ko karshe abu a cikin wani musamman lissafi. Idan da dauki sauki abubuwa, su misali kadan na samuwar ne ya daidaita da sifili, Ina nufin, irin aka gyara da wani sakamako a kan sakamakon samu ta hanyar lissafin. Ka yi kokarin amfani da bayani a kan wani takamaiman dauki. Idan muka dauki matsayin misali aiwatar da samuwar na baƙin ƙarfe oxide (Fe ³⁺⁾ m karfe ta maida martani tare da graphite, da tunani darajar za a iya samu misali heats samuwar. Domin baƙin ƙarfe oxide (Fe ³⁺⁾ shi zai zama -822,1 KJ / mol ga graphite (sauki abu) shi ne sifili. A sakamakon dauki samar carbon monoxide (CO), ga abin da nuna alama yana da darajar da - 110,5 KJ / mol, yayin da zafin samuwar saki baƙin ƙarfe yayi dace da sifili. Rikodi misali heats na samuwar wannan sinadaran hulda ne halin kamar haka:

_{Game da} 298? H = 3 × (-110,5) - (-822,1) = -331,5 + 822,1 = 490,6 KJ.

Nazarin samu ta hanyar dokar Hess Tazarar sakamakon, yana yiwuwa su yi ma'ana ƙarshe cewa tsari ne da wani endothermic hira, Ina nufin shi ya wallafasu zatrachivaniya makamashi baƙin ƙarfe rage dauki na ta ferric oxide.