Kuchinja kweEnthalpy neEnthalpy
Nhanganyaya kuEnthalpy
Enthalpy ipfungwa inokosha yethermodynamic mukemistri nefizikisi. Izwi rekuti enthalpy rinobva pashoko rechiGiriki rekare rinoreva "kupisa mukati" (en rinoreva "mukati" uye thalpein rinoreva "kupisa"). Pfungwa iyi yakatanga kuunzwa nenyanzvi yefizikisi yekuDutch Heike Kamerlingh Onnes mukutanga kwezana remakore rechi20. Muchidimbu, enthalpy inotsanangura huwandu hwesimba riri musystem inokwanisa kushanda nekumanikidzwa nguva dzose.
Pamasvomhu, enthalpy (H) inoratidzwa se:
\[ H = U + PV \]
Kupi
– \( H \) ndiyo enthalpy,
– \( U \) isimba remukati mehurongwa,
– \( P \) ndiko kumanikidzwa, uye
– \( V \) ivhoriyamu.
Enthalpy imhando yakakura, zvichireva kuti kukosha kwayo kunoenderana nehuwandu hwezvinhu zviri musystem. Inokosha zvikuru mumaitiro ethermodynamic uye maitiro emakemikari nekuti shanduko mu enthalpy inogona kushandiswa kuona huwandu hwesimba rinoburitswa kana kunyudzwa mukuita.
Basa reEnthalpy muKuita kweMakemikari
Munguva yekuchinja kwemakemikari, zvisungo zvemakemikari pakati pemaatomu nemamorekuru zvinotyoka uye zvinogadziriswa. Maitiro aya anosanganisira shanduko yesimba rinogona kusunungurwa kana kutorwa nehurongwa. Simba iri rinowanzo kuyerwa maererano nekushanduka kwe enthalpy (\( \Delta H \)).
Kana shanduko ye enthalpy iri negative (\( \Delta H < 0 \)), reaction yacho i exothermic, zvichireva kuti inoburitsa simba kunzvimbo dzakakomberedza. Muenzaniso wakajairika we exothermic reaction ndeyekupisa, uko mafuta anosangana neokisijeni kuti abudise kupisa nechiedza.
Kusiyana neizvi, kana shanduko ye enthalpy iri yakanaka (\( \Delta H > 0 \)), mhinduro yacho i endothermic, zvichireva kuti inotora simba kubva kunharaunda. Muenzaniso we endothermic reaction i photosynthesis, umo zvirimwa zvinotora simba rezuva kuti zvishandure kabhoni dioxide nemvura kuita glucose neokisijeni.Kuverenga Kuchinja kweEnthalpy
Kuti tiverenge shanduko ye enthalpy mu chemical reaction, tinowanzo shandisa calorimetric data kana Hess's law. Kuchinja kwe enthalpy kwakajairika (\( \Delta H^\circ \)) kuchinja kwe enthalpy kwe reaction kunoitika pakumanikidzwa kwe 1 atm uye tembiricha chaiyo (kazhinji 25°C kana 298 K).
Data reCalorimetry
Calorimetry inzira yekuedza inoshandiswa kuyera huwandu hwekupisa hunobatanidzwa mukuita kwemakemikari. Chishandiso chinoshandiswa mukuyedza uku chinonzi calorimeter. Tichishandisa calorimeter, tinogona kuyera shanduko yekupisa inoitika panguva yekuita, iyo inogona kushandurwa kuita shanduko mu enthalpy.
Mutemo waHess
Mutemo waHess unoti kuchinja kwese kwe enthalpy kwemakemikari hakuenderane nenzira yainoenda, asi zvinoenderana chete nemamiriro ekutanga neekupedzisira. Izvi zvinoreva kuti tinogona kushandisa data rinozivikanwa kubva muzvikamu zvakasiyana-siyana zve reaction kuti tiverenge kuchinja kwese kwe enthalpy. Semuenzaniso, kana reaction ikakamurwa kuita matanho madiki akati wandei ane shanduko dzinozivikanwa dze enthalpy, tinogona kusanganisa enthalpies dzedanho rega rega kuti tiwane kuchinja kwese kwe enthalpy.
Mutemo waHess unogona kutsanangurwa nenzira iri nyore:
\[ \Delta H_{\text{total}} = \sum \Delta H_{\text{reaction}} \]
Mashandisirwo eEnthalpy muIndasitiri
Pfungwa dzekuchinja kwe enthalpy ne enthalpy dzakakosha mumaindasitiri akasiyana-siyana, kunyanya ayo ane chekuita nesimba nemakemikari. Mamwe mashandisirwo akakosha anosanganisira:
Indasitiri yeSimba
Muindasitiri yekugadzira simba, ingave mafuta efossil, simba renyukireya, kana simba rinogona kushandiswazve, kushanda zvakanaka kwesystem kunoenderana zvakanyanya ne enthalpy. Semuenzaniso, mufekitori yesimba remhepo, kushanda zvakanaka kwethermodynamic kunoenderana nemusiyano we enthalpy pakati pezvinopinzwa (kazhinji mvura yemvura) uye zvinobuda (superheated steam). Kugadzirisa shanduko iyi ye enthalpy kunogona kuvandudza kushanda zvakanaka kwesimba.
Industri Kimia
Muindasitiri yemakemikari, kunzwisisa shanduko dze enthalpy kwakakosha pakugadzira maitiro anoshanda uye kudzora mafambiro e exothermic kana endothermic. Semuenzaniso, mukugadzirwa kweammonia kuburikidza nemaitiro eHaber, shanduko dze enthalpy dzinoshandiswa kufanotaura uye kudzora mamiriro ekuita kuti uwane goho rakanaka.
Indasitiri yezvekudya neMishonga
Mumaindasitiri ezvekudya nemishonga, shanduko dze enthalpy dzinoshandiswa kugadzira nekugadzirisa maitiro akadai se pasteurization, sterilization, uye kuomesa. Maitiro aya anowanzoda kudzora tembiricha zvakanyanya kuti chigadzirwa chive nechokwadi chekuchengetedzwa uye mhando, saka kunzwisisa kwakanaka kweshanduko dze enthalpy kwakakosha.
Chidzidzo Chenyaya: Kuchinja KweEnthalpy Mumaitiro EHaber
Maitiro eHaber muenzaniso wakanaka wekushandiswa kwekuchinja kwe enthalpy muindasitiri yemakemikari. Maitiro aya anoshandiswa kugadzira ammonia (\( NH_3 \)) kubva kunitrogen (\( N_2 \)) uye hydrogen (\( H_2 \)).
Maitiro emakemikari anoitika ndeaya:
\[ N_2 (g) + 3 H_2 (g) \museve wekurudyi 2 NH_3 (g) \]
Kuita uku kunobva mu exothermic ine shanduko yakajairwa ye enthalpy yeinenge \( \Delta H = -92.4 \, \text{kJ/mol} \). Vachiziva kuti kuita uku kunoburitsa simba, mainjiniya emakemikari vanogona kugadzira reactor kuti vadzore kupisa kunoburitswa uye kuwedzera goho reammonia.
Mhedziso
Kuchinja kwe enthalpy ne enthalpy ipfungwa huru mu thermodynamics ne chemistry dzinotibatsira kunzwisisa nekudzora simba mu system. Kubva pakuita kwemakemikari kuri nyore kusvika kumaitiro akaomarara emaindasitiri, kuchinja kwe enthalpy kunoita basa rakakosha mukushanda nesimba uye kushanda zvakanaka kwesimba. Nekunzwisisa nekushandisa pfungwa idzi, tinogona kugadzira maitiro ari nani, anoshanda zvakanyanya, uye ane hushamwari kune zvakatipoteredza mumaindasitiri akasiyana-siyana.
