UVan der Walls igama lesazi sefiziksi saseDashi, uJD van der Waals (1837-1923). I-Van der Waals Equation of State iyi-equation of state of a gas, efana ne-Equation of state of an ideal gas. Umehluko uwukuthi, I-equation of state of an ideal gas ayikwazi ukunikeza imiphumela enembile uma ingcindezi kanye nobuningi begesi yangempela kukhulu ngokwanele. Kanti i-Equation of State kaVan der Waals ingaveza imiphumela enembile kakhudlwana.
Ukuba khona kwalesi sibalo kuvela kuVan der Waals, owaqaphela ukulinganiselwa kwesibalo sesimo esifanele. Ama-Waals, shintsha isibalo sesimo segesi esifanele, ngokungeza izici eziningana ezithinta nesimo segesi yangempela, lapho ingcindezi kanye nobuningi begesi yangempela kukhulu.
Umfutho wegesi ulingana nomthamo ngendlela ephambene. Uma umfutho wegesi ukhuphuka, umthamo wegesi uyancipha. Ngokuphambene nalokho, uma umthamo wegesi uyancipha, umfutho wegesi uyanda. Lapho umthamo wegesi uncipha, ubuningi begesi buyanda (ubuningi = isisindo / ivolumu). Kungashiwo ukuthi umfutho ulingana ngqo nobuningi. Uma umfutho wegesi umkhulu, ubuningi begesi nabo bukhulu. Ngokuphambene nalokho, uma umfutho wegesi uncane, ubuningi begesi nabo buncane. Umfutho wegesi nawo ulingana ngqo nokushisa. Uma umfutho wegesi ukhuphuka, izinga lokushisa legesi liyanda. Singaphetha ngokuthi uma umfutho wegesi ukhuphuka, izinga lokushisa, kanye nobuningi begesi, kuyilapho ubuningi begesi buncipha.
Uma ivolumu yegesi yehla, ibanga eliphakathi kwama-molecule liyasondela. Uma ibanga eliphakathi kwama-molecule lisondela, ama-molecule ayadonselana. Kufana nalapho ucezu lwensimbi lusondela kumagnet. Uma ibanga eliphakathi kukamagnet nensimbi lide ngokwanele, imagnet ayikwazi ukudonsa insimbi. Kodwa uma ibanga eliphakathi kukamagnet nensimbi liseduze, insimbi iyadonswa eduze. Lapho ama-molecule esezoshayisana, ama-electron angaphandle kwe-molecule ayaxoshana (ukuxoshwa kukagesi). Ngenxa yalokho, ama-molecule awakwazi ukunamathelana. Kusukela kule ncazelo emfushane, kungashiwo ukuthi amandla okudonsa phakathi kwama-molecule athonya isimo segesi.
Uma ingcindezi yegesi inkulu ngokwanele, futhi ivolumu yegesi iba ncane, ibanga phakathi kwama-molecule liyasondela. Ngoba ama-molecule nawo anosayizi (ububanzi be-athomu = 10-10 m), khona-ke sidinga futhi ukucabangela ivolumu yala ma-molecule.
I-Van der Waals yehlisa i-equation of state, uma kucatshangelwa ivolumu yama-molecule kanye nokusebenzisana okwenzeka phakathi kwama-molecule. I-equation etholwe yi-Van der Waals ingumphumela wokuguqulwa kwe-equation ye-gas state efanele i-PV = n R T. I-Van der Waals I-equation of State:
P = ingcindezi yegesi (N / m2 = Pa)
V = ivolumu yegesi (m3)
R = igesi engaguquki yonke (R = 8.315 J / mol. K = 8315 kJ / kmol. K)
T = izinga lokushisa (K)
a = ukungaguquguquki okwenziwa yi-empirical (inani lincike emandleni okukhanga phakathi kwama-molecule egesi)
b = ukungaguquguquki kobufakazi (okumelela ivolumu ye-mole eyodwa yama-molecule egesi)
n = Inani lama-moles (mol)
bn = ivolumu ephelele yama-molecule egesi
Ama-constant a no-b atholakala ngokuhlolwa. Amanani angaguquki u-a no-b ancike ohlotsheni lwegesi.
n2 /V2 = isilinganiso se-quadratic senani lama-moles (n) nesikwele somthamo wegesi (V). Inani lika-n2 /V2 kuncike ekucindezelweni nasekubuneni kwegesi. Uma umfutho wegesi (P) mkhulu, khona-ke umthamo wegesi (V) mncane. Uma u-V omncane, omkhulu u-n2 /V2Uma ivolumu yegesi incane (n2 /V2 likhulu) ibanga eliphakathi kwama-molecule liseduze. Lapho ibanga eliphakathi kwama-molecule lisondela, kulapho ukuxhumana phakathi kwala ma-molecule (ukushayisana, ukudonsana ndawonye) kukhulu. Ngakho-ke, n2 /V2 ilingana ngqo nesilinganiso esiqhubekayo (qhathanisa nesibalo sika-van der Waals). Inani lika-n likhula kakhulu2 /V2, kulapho ukukhangana phakathi kwama-molecule (a) kukhulu khona.
Ngakolunye uhlangothi, uma ingcindezi yegesi (P) incane, khona-ke umthamo wegesi (V) uba mkhulu. Uma u-V ebonakala kakhulu, u-n uba mncane.2 /V2. Okuphansi kwe-n2 /V2, amandla akhangayo phakathi kwama-molecule ayancipha.
(V – bn) = Umehluko phakathi kwevolumu yegesi kanye nevolumu iyonke yama-molecule egesi. I-b engaguquki imelela ivolumu ye-mole eyodwa yama-molecule egesi. n = inani lama-mole. Umkhiqizo wesikhathi esiphakathi kuka-b no-n (bn) = ivolumu iyonke yama-molecule egesi. Uma ingcindezi yegesi (P) iba nkulu kakhulu, khona-ke ivolumu yegesi (V) iba ncane.
Uma u-V omncane, omncane (V – bn). Lokhu kusho ukuthi ibanga phakathi kwama-molecule liyakhula, futhi-ke, ukukhangana phakathi kwama-molecule kuyanda. Ngokuphambene nalokho, uma ingcindezi yegesi iba ncane, umthamo wegesi uba mkhulu. Uma umthamo wegesi ubalulekile, kulapho uphakama khona (V – bn). Uma ukhulu (V – bn), kulapho ukukhangana phakathi kwama-molecule egesi kuba kuncane.
Singasho ukuthi i-equation yesimo se-van der Waals ichaza isimo segesi sangempela ngokunembe kakhulu kune-equation yegesi efanele. Uma ingcindezi kanye nobuningi begesi kukhulu ngokwanele, i-equation ye-van der Waals inikeza imiphumela enembe kakhudlwana. Uma ingcindezi yegesi ingenkulu kakhulu, khona-ke (i-an2 /V2) kanye (V-bn) kungashaywa indiva, ukuze i-Van der Waals state equation ishintshe ibe yi-equation ye-gas state efanele.
