Ubudlelwano Phakathi Kokucindezeleka Nokushisa
Ukucindezela kanye nokushisa kuyizinto ezimbili ezibonakalayo ezihlobene kakhulu, ikakhulukazi uma sixoxa ngamagesi. Empilweni yansuku zonke, ubudlelwano phakathi kwalokhu kokubili bungabonakala emathayini ezimoto azizwa "enzima" ngemva kokusetshenziswa isikhathi eside, amathini e-aerosol okungafanele afudunyezwe, ngisho naseziphekweni zokucindezela ezisheshisa inqubo yokupheka. Nakuba kubonakala kulula, ubudlelwano phakathi kokucindezela kanye nokushisa bunesisekelo esiqinile sesayensi kumbono we-kinetic wamagesi kanye nemithetho ye-thermodynamics. Lesi sihloko sixoxa ngendlela ukucindezela kanye nokushisa okuthintana ngayo, amafomula achaza lokhu, kanye nezibonelo zokusetshenziswa kwawo.
Ukuqonda imiqondo eyisisekelo: ingcindezi kanye nokushisa
Ukucindezela kuchazwa njengamandla endaweni ngayinye. Uma kukhulunywa ngamagesi, ukucindezela kuvela ngoba ama-molecule egesi ahamba ngokungahleliwe futhi ashayisane nezindonga zesitsha. Uma lokhu kushayisana kuvame futhi kunamandla, kulapho ukucindezela kuba kukhulu khona. Iyunithi ye-SI yokucindezela yi-pascal (Pa), kodwa empeleni, ama-atmospheres (atm), ibha, noma i-mmHg avame ukusetshenziswa.
Izinga lokushisa liyisilinganiso samandla ajwayelekile e-kinetic wezinhlayiya ezakha into ethile. Njengoba izinga lokushisa likhuphuka, izinhlayiya zihamba ngokushesha; njengoba izinga lokushisa lehla, ukunyakaza kwazo kuyehla. Iyunithi ye-SI yokushisa yi-kelvin (K), yize izinga le-Celsius (°C) livame ukusetshenziswa empilweni yansuku zonke. Ekubalweni kwamagesi afanele, i-kelvin ibalulekile ngoba isikali siqala ku-absolute zero (0 K), iphuzu lapho amandla e-kinetic ezinhlayiya esezingeni eliphezulu okungenani.
Ubudlelwano phakathi kokucindezela kanye nokushisa bucaca uma sihlanganisa izincazelo ezimbili ezingenhla: izinga lokushisa linquma ukuthi izinhlayiya zihamba ngokushesha kangakanani, kuyilapho ingcindezi incike emiphumeleni yezinhlayiya ezindongeni zesitsha. Njengoba izinhlayiya zihamba ngokushesha (ukushisa okwandayo), ukushayisana kuba njalo futhi kuqine, ngakho ingcindezi ivame ukwanda—uma nje ivolumu ingashintshi, vele.
Ithiyori ye-Kinetic: kungani ingcindezi ikhuphuka njengoba izinga lokushisa likhuphuka?
Ngokusho kwemfundiso ye-kinetic yamagesi, amagesi akhiwa yizinhlayiya ezihamba ngokungahleliwe futhi zishayisane. Emazingeni okushisa aphezulu, amandla ajwayelekile e-kinetic ezinhlayiya ayanda. Ngenxa yalokho:
1. Imvamisa yokushayisana iyanda: izinhlayiya zihamba ngokushesha esikhaleni esingaphakathi kwesitsha, ngakho-ke zishaya izindonga kaningi.
2. Umfutho wokushaya ukhulu: lapho inhlayiya ishesha, ushintsho emgudwini wayo lapho igxuma nalo lukhulu.
3. Umfutho ophelele uyakhuphuka: ngoba umfutho uwumphumela wamandla aqongelelwe emitheleleni yezinhlayiya ezindongeni zesitsha.
Kusukela kulo mbono, ubudlelwano phakathi kwengcindezi kanye nokushisa akuyona nje ifomula, kodwa umphumela oqondile wokunyakaza kwezinhlayiya ezincane kakhulu.
Umthetho kaGay-Lussac: ingcindezi ilingana ngqo nokushisa (ivolumu eqhubekayo)
Ngegesi esitsheni esivaliwe esinomthamo ongaguquki (isb. isilinda segesi noma ithini le-aerosol), ubudlelwano phakathi kwengcindezi nokushisa buvezwa nguMthetho kaGay-Lussac:
\[
\frac{P}{T} = okungaguquki
\]
noma ngesimo sezimo ezimbili:
\[
\frac{P_1}{T_1} = \frac{P_2}{T_2}
\]
Lapha \(P\) ingcindezi kanye \(T\) izinga lokushisa ku-Kelvin. Lo mthetho uthi ingcindezi yegesi ilingana ngqo nezinga lokushisa eliphelele uma ivolumu kanye nenani lama-mole egesi kuhlala kungaguquki. Lokhu kusho ukuthi uma izinga lokushisa (ku-K) liphindwe kabili, ingcindezi nayo iphinda kabili.
Isibonelo esilula: uma ithubhu eliqukethe igesi liku-300 K ngokucindezela okungu-1 atm, khona-ke izinga lokushisa lenyuka laya ku-360 K, khona-ke ukucindezela kuba:
\[
P_2 = P_1 \izikhathi \frac{T_2}{T_1} = 1 \izikhathi \frac{360}{300} = 1{,}2 \umbhalo{atm}
\]
Lokhu kwanda okungu-20% kungase kubonakale kukuncane, kodwa ngaphansi kwezimo ezithile kungaba yingozi, ikakhulukazi uma isilinda singaklanyelwe ukumelana nomfutho ophezulu.
Umthetho wegesi ofanele: ubudlelwano obuphelele phakathi kwe-P, V, kanye ne-T
Ukuze siqonde ubudlelwano phakathi kwengcindezi kanye nokushisa ngokugcwele, sisebenzisa i-equation yegesi efanele:
\[
I-PV = nRT
\]
Nge:
– \(P\) = ingcindezi
– \(V\) = ivolumu
– \(n\) = inani lama-moles egesi
– \(R\) = i-gas constant efanele
– \(T\) = izinga lokushisa eliphelele (K)
Uma i-\(n\) kanye ne-\(V\) zilungisiwe, khona-ke:
\[
P \propto T
\]
Lokhu kubuyele emthethweni kaGay-Lussac. Kodwa-ke, amagesi afanele abonisa nokuthi ubudlelwano phakathi kokucindezela nokushisa bungashintsha uma ivolumu ishintsha. Isibonelo, ebhaluni elinwebekayo, lapho izinga lokushisa likhuphuka, ibhaluni linganda (likhuphuke ngevolumu), ngakho-ke ingcindezi ayikhuli njalo njengasesitsheni esiqinile.
Indima yevolumu: kungani zonke izinhlelo zingabi nokwanda kwengcindezi okufanayo?
Ezweni langempela, izitsha eziningi aziqinile ngokuphelele. Uma igesi ishiswa, kunezindlela ezimbili ezingase ziphendulwe:
1. Ivolumu eqinile (isitsha esiqinile): ingcindezi iyanda kakhulu.
2. Ukwanda kwevolumu (isitsha esiguquguqukayo): eminye “imiphumela” yokushisa iphenduka ukwanda kwevolumu, ngakho-ke ingcindezi inganda kancane, ihlale ifana, noma ikhuphuke kodwa hhayi kakhulu njengasendabeni yevolumu engaguquki.
Isibonelo ibhaluni lomoya oshisayo. Umoya ongaphakathi kwebhaluni uyashiswa, okwenza ubuningi bawo bunciphe, wandise ibhaluni, futhi wandise ukuntanta. Ukucindezela okungaphakathi kwebhaluni kuvame ukusondela ekucindezelekeni komoya ngoba ibhaluni livulekile phansi (noma linomshini ovimbela ukucindezela ukuthi kwande kakhulu). Ngakho-ke, ukushisa kuthinta kakhulu ivolumu kanye nobuningi, kunokuba kukhulise kakhulu ukucindezela.
Izibonelo zokusetshenziswa empilweni yansuku zonke
1. Amathayi emoto
Umfutho wamathayi ungakhuphuka ngemva kohambo olude. Ukungqubuzana phakathi kwethayi nomgwaqo kanye nokuguquguquka kudala ukushisa, okuphakamisa izinga lokushisa lomoya ngaphakathi kwethayi. Ngenxa yokuthi umthamo wamathayi uhlala ungaguquguquki (nakuba ushintshashintsha kancane), umfutho wamathayi ugcina ukhuphuka. Yingakho kuthathwa izilinganiso zomfutho wamathayi uma amathayi "ebanda."
2. Amathini e-aerosol
Amathini e-aerosol aqukethe amagesi acindezelwe kanye noketshezi. Uma eshiswa, izinga lokushisa legesi liyakhuphuka futhi ingcindezi iyakhuphuka. Ngenxa yokuthi ithini liqinile futhi livaliwe, isimo siseduze nomthamo oqhubekayo, okuvumela ingcindezi ukuthi ikhuphuke kakhulu. Yingakho izixwayiso "ungashi" noma "ungagcini ezindaweni ezishisayo" zivame ukusetshenziswa.
3. Isitofu sokucindezela
Izipheki zokucindezela zisebenza ngokwandisa ingcindezi yomhwamuko wamanzi angaphakathi ebhodweni. Njengoba ingcindezi ikhuphuka, izinga lokubila lamanzi nalo liyakhuphuka, okuvumela ukudla ukuthi kuphekwe emazingeni okushisa angaphezu kuka-100°C ngaphandle kokuba amanzi aphele ngokushesha. Lapha, ubudlelwano bokucindezela nokushisa buhlobene nokulingana kwesigaba (amanzi acwebezelayo kanye nomhwamuko), hhayi nje amagesi afanele, kodwa nomgomo ojwayelekile uhlala: izinhlelo ezicindezelwe zivumela amazinga okushisa aphezulu okusebenza.
4. Izinhlelo zokupholisa kanye ne-AC
Emjikelezweni wokuqandisa, i-refrigerant iyacindezelwa futhi inwetshwe. Uma icindezelwe, ingcindezi yayo iyanda futhi izinga lokushisa layo livame ukwanda. I-refrigerant ibe isikhipha ukushisa endaweni ezungezile bese ishintsha isigaba. Ubudlelwano phakathi kwengcindezi kanye nezinga lokushisa ku-refrigerant bubalulekile ekusebenzeni kahle nasekuphepheni kohlelo.
Izimo zangempela: ukuphambuka kusuka kugesi ofanele
Umthetho kaGay-Lussac kanye nesilinganiso segesi esifanele kunembile kakhulu ekucindezelekeni okuphansi kanye nasezingeni lokushisa eliphakeme, lapho ukusebenzisana kwama-molecule kunganakwa. Ekucindezelekeni okuphezulu noma emazingeni okushisa aphansi, amagesi angempela angaphambuka ngoba:
- amandla aphakathi kwama-molecule okukhanga,
– usayizi wama-molecule ongenakunakwa,
– kungenzeka ukuthi ukuminyana kusondela eqophelweni lokugcwala.
Ngaphansi kwalezi zimo, ubudlelwano phakathi kwengcindezi kanye nokushisa buhlala bukhona, kodwa ifomula idinga imodeli yangempela yegesi (isb., i-Van der Waals equation) noma idatha ye-empirical.
Isiphetho
Ubudlelwano phakathi kokucindezela nokushisa bungumqondo obalulekile ku-physics nobunjiniyela. Ngokwe-microscopic, izinga lokushisa linquma isivinini lapho izinhlayiya zegesi zihamba khona, kuyilapho ingcindezi ivela ekushayweni kwezinhlayiya ezindongeni zesitsha. Esitsheni esinevolumu engaguquki, ingcindezi ilingana ngqo nokushisa okuphelele, njengoba kushiwo umthetho kaGay-Lussac. Sisebenzisa i-equation yegesi efanele, sibona ukuthi lobu budlelwano buxhomeke kumthamo nobuningi begesi. Ukusetshenziswa kwayo kubanzi, kusukela emathayini ezimoto kanye nama-aerosol kuya eziphekeni zokucindezela kanye nezinhlelo zokuqandisa. Ukuqonda ubudlelwano phakathi kokucindezela nokushisa akusisizi nje kuphela ukubala ubuningi obubonakalayo kodwa futhi kuthuthukisa ukuphepha nokusebenza kahle kobuchwepheshe obuningi bansuku zonke.
