Ukungaguquki kokulingana: ukubhala u-K, ukufunda u-Q nokuguqula u-Kc ube u-Kp

Ukulingana okunyakazayo: okuya phambili nokuphambene ngamazinga alinganayo

Ekusabeleni okungaphenduka, imikhiqizo ingasabela ukwakha kabusha izisabelo. Njengoba ukusabela okuya phambili kusebenzisa izisabelo kuyanensa, futhi njengoba imikhiqizo inqwabelana ukusabela okuphambene kuyashesha. Ukulingana kufinyelelwa lapho la mazinga amabili elingana. Kusukela lapho, ukugxila kuhlala kungaguquki nakuba kokubili ukusabela kuqhubeka. Yingakho osokhemisi bekubiza ngokuthi ukulingana okunyakazayo futhi bakubhale ngomcibisholo ophindwe kabili, ⇌.

Ukwakheka okufanayo kokulingana kungafinyelelwa kusukela kunoma yiluphi uhlangothi. Ifulaski evaliwe eqala nge-NO₂ ehlanzekile neyevolumu efanayo eqala ngenani elilinganayo le-N₂O₄ ehlanzekile ziphetha ngengxube efanayo lapho zigcinwe ezingeni lokushisa elifanayo. Ukulingana kufinyelelwa kuphela kusistimu evaliwe; uma umkhiqizo uphunyuka, njengoba i-CO₂ yenza esitsheni esivulekile, ukusabela akulokothi kuzinze.

Ukwakha isisho sika-K kusuka esibalweni esilinganisiwe

Ekusabeleni okujwayelekile aA + bB ⇌ cC + dD, umthetho we-mass action unikeza okungaguquki kokulingana ngokokugxila kwe-molar: Kc = [C]ᶜ[D]ᵈ / ([A]ᵃ[B]ᵇ). Imikhiqizo iya phezulu, izisabelo phansi, futhi ukugxila ngakunye kuphakanyiswa emandleni e-coefficient yakho. Ngokungafani nomthetho wezinga, lesi sisho sivela ngqo esibalweni esilinganisiwe.

Izinto eziqinile ezihlanzekile noketshezi oluhlanzekile kuyashiywa, ngoba ukugxila kwakho okusebenzayo akushintshi njengoba ukusabela kuqhubeka. Amanzi nawo ayashiywa lapho eyisincibilikisi esixazululweni samanzi esihlanjululiwe. Isibonelo, ukubola CaCO₃(s) ⇌ CaO(s) + CO₂(g) kuno-Kc = [CO₂]. Ezingeni lokushisa elithile, ingcindezi yokulingana ye-CO₂ ngaphezu kwezinto eziqinile inqunyiwe, noma ngabe amanani alezi zinto ezimbili eziqinile angakanani.

Ngokuqinile, okungaguquki kokulingana kwakhiwa ngama-activity, angenawo amayunithi, ngakho u-K ubikwa ngaphandle kwamayunithi. Ukusebenzisa ukugxila ngo-mol/L noma izingcindezi ngo-atm noma ngo-bar kuwukulinganisela okuvamile kukhemistri evamile.

Ukufunda ubukhulu buka-K

U-K omkhulu usho ukuthi ekulinganeni imikhiqizo iyabusa; u-K omncane usho ukuthi izisabelo ziyabusa. Njengesiqondiso esilinganiselwe, u-K omkhulu kuno-10³ cishe usho ukuthi ukusabela kucishe kuphelele, u-K omncane kuno-10⁻³ cishe usho ukuthi kwakheka umkhiqizo omncane, futhi amanani aphakathi anikeza ingxube enamanani abalulekile kokubili.

Isigaba 13.4 se-OpenStax sinikeza u-Kc = 4.1 × 10⁻⁴ ku-N₂(g) + O₂(g) ⇌ 2 NO(g) ku-2000 °C. Ngisho nakulelo zinga lokushisa, umoya uqukethe i-NO encane kuphela ekulinganeni. Ezingeni lokushisa legumbi okungaguquki kuncane kakhulu nakakhulu, yingakho i-nitrogen ne-oxygen kuhlala ndawonye emkhathini.

U-K akasho lutho ngesivinini. Ukusabela okuno-K omkhulu kakhulu kusengahamba kancane kakhulu ukuthi kubonwe. I-kinetics, hhayi okungaguquki kokulingana, enquma ukuthi ukulingana kufinyelelwa ngokushesha kangakanani.

Isibonelo esisebenzile: u-Kc no-Kp we-nitrogen dioxide ne-dinitrogen tetroxide

Ekusabeleni okubandakanya amagesi, okungaguquki kokulingana kungabhalwa nangezingcindezi ezingxenye, kunikeze u-Kp. Lokhu kokubili kuhlobene ngo-Kp = Kc(RT)^Δn, okusho u-Kc ophindaphindwe ngo-RT ophakanyiswe emandleni Δn, lapho u-Δn engama-mole emikhiqizo yegesi ukususa ama-mole ezisabelo zegesi, R = 0.08206 L atm mol⁻¹ K⁻¹ lapho izingcindezi zingu-atm, no-T ungama-kelvin. Lapho Δn = 0, u-Kp ulingana no-Kc.

Isigaba 13.2 se-OpenStax sichaza u-0.10 mol we-NO₂ obekwe efulaskini engu-1.0 L ku-25 °C, efika ekulinganeni no-[NO₂] = 0.016 mol/L no-[N₂O₄] = 0.042 mol/L. Njengokuhlola, 0.016 + 2(0.042) = 0.100 mol/L, ngakho yonke i-nitrogen ibaliwe. Ku-N₂O₄(g) ⇌ 2 NO₂(g), Kc = [NO₂]²/[N₂O₄] = (0.016)² / 0.042 = 6.1 × 10⁻³, ezinombolweni ezibalulekile ezimbili.

Lapha Δn = 2 − 1 = 1, futhi RT = 0.08206 × 298.15 = 24.47. Ngakho Kp = (6.1 × 10⁻³)(24.47) = 0.15, izingcindezi zingu-atm. Inani likhulu kuno-Kc ngoba u-Δn muhle futhi u-RT mkhulu kuno-1.

Ukushintsha isibalo kushintsha u-K

Ngoba u-K wakhiwa kusuka esibalweni esilinganisiwe, noma yiluphi ushintsho esibalweni lushintsha u-K ngendlela engabikezelwa. Le mithetho iwumlingani wokulingana wemithetho yokuphatha u-ΔH emthethweni ka-Hess, ukuphindaphinda kuthatha indawo yokwengeza.

Isibonelo esisebenzile. Qala ku-N₂(g) + O₂(g) ⇌ 2 NO(g), Kc = 4.1 × 10⁻⁴ ku-2000 °C. Ukusiphendula kunikeza 2 NO(g) ⇌ N₂(g) + O₂(g) no-Kc = 1/(4.1 × 10⁻⁴) = 2.4 × 10³. Ukwehlisela isibalo sokuya phambili engxenyeni kunikeza ½ N₂(g) + ½ O₂(g) ⇌ NO(g) no-Kc = √(4.1 × 10⁻⁴) = 2.0 × 10⁻². Uma wenza kokubili, NO(g) ⇌ ½ N₂(g) + ½ O₂(g) uno-Kc = 1/√(4.1 × 10⁻⁴) = 49.

• Phendula isibalo: u-K omusha ngu-1/K.
• Phindaphinda yonke i-coefficient ngo-n: u-K omusha ngu-Kⁿ. Ukwehlisela isibalo engxenyeni kuthatha i-square root.
• Engeza izibalo ezimbili: phindaphinda amanani azo ka-K. Womabili amanani ka-K kufanele abe ezinga lokushisa elifanayo.

Ukuqhathanisa u-Q no-K ukubikezela indlela

I-reaction quotient, Q, inefomu elifana ncamashi nelika-K kodwa isebenzisa ukugxila okukhona nganoma yisiphi isikhathi, hhayi ekulinganeni kuphela. Ukuqhathanisa u-Q no-K kukutshela ukuthi ukusabela kufanele kuye ngakuphi. Uma Q < K, umkhiqizo mncane kakhulu, futhi ukusabela kuya phambili. Uma Q > K, umkhiqizo muningi kakhulu, futhi ukusabela kuya emuva. Uma Q = K, isistimu isekulinganeni.

Isibonelo esisebenzile. Isigaba 13.2 se-OpenStax sinikeza u-Kc = 0.640 ku-800 °C ku-CO(g) + H₂O(g) ⇌ CO₂(g) + H₂(g). Ingxube iqukethe [CO] = 0.0500, [H₂O] = 0.0400, [CO₂] = 0.0300 no-[H₂] = 0.0600 mol/L. Q = (0.0300)(0.0600) / [(0.0500)(0.0400)] = 0.00180/0.00200 = 0.900. U-Q mkhulu kuno-K, ngakho ingxube ishintshela ku-CO naku-H₂O.

Ingxube yesibili ine-CO ne-H₂O efanayo kodwa [CO₂] = 0.0200 no-[H₂] = 0.0250 mol/L. Manje Q = (0.0200)(0.0250)/(0.00200) = 0.250, okungaphansi kuka-0.640, ngakho le ngxube isabela iye phambili futhi yenza i-CO₂ ne-H₂ eningi.

Isibonelo esisebenzile: u-K kusuka engxubeni yokulingana elinganisiwe

Ukulinganisa inani elilodwa lokulingana ngokuvamile kwanele ukuthola u-K, ngoba isibalo esilinganisiwe sinquma ukuthi lonke elinye inani lashintsha kanjani. Idatha lapha iyisibonelo. Ezingeni lokushisa elilodwa elingaguquki, u-0.500 mol we-PCl₅ uvalelwa efulaskini engenalutho engu-2.00 L futhi uvunyelwe ukufika ku-PCl₅(g) ⇌ PCl₃(g) + Cl₂(g). Ekulinganeni ifulaski iphethe u-0.180 mol we-Cl₂.

Sebenza ngokugxila. U-[PCl₅] wokuqala ungu-0.500 mol / 2.00 L = 0.250 mol/L, futhi u-[Cl₂] wokulingana ungu-0.180 mol / 2.00 L = 0.0900 mol/L. I-mole ngayinye ye-Cl₂ eyakhiwe nayo yakha i-mole eyodwa ye-PCl₃ futhi isebenzise i-mole eyodwa ye-PCl₅, ngakho [PCl₃] = 0.0900 mol/L no-[PCl₅] = 0.250 − 0.0900 = 0.160 mol/L. Bese Kc = (0.0900)(0.0900)/0.160 = 0.0506. Kuleli zinga lokushisa, amaphesenti angu-36.0 e-PCl₅ abola. Isihlahlandlela samatafula e-ICE sinweba lokhu kubala kuye ezinkingeni lapho kufanele uxazulule khona amanani okulingana.

Amaphutha ezisho zokulingana

Uhlu olufushane lokuhlola lubamba amaphutha amaningi ekubhaleni nasekusebenziseni u-K.

• Ukubeka izisabelo phezulu. U-K uhlala eyimikhiqizo phezu kwezisabelo esibalweni njengoba sibhaliwe.
• Ukushiya ama-coefficient njengama-exponent, noma ukuwasebenzisa njengeziphindaphindi esikhundleni salokho.
• Ukufaka into eqinile ehlanzekile, uketshezi oluhlanzekile noma amanzi ayisincibilikisi esishweni.
• Ukusebenzisa ukugxila kokuqala ku-K. Amanani okulingana kuphela angena ku-K; noma iliphi elinye iqoqo linikeza u-Q.
• Ukukhohlwa ukuthi u-K uncike ezingeni lokushisa. Inani lika-K alinancazelo ngaphandle kwezinga lokushisa elisebenza kulo.
• Ukuguqula u-Kc ube u-Kp no-Δn obalwe kuzo zonke izinhlobo esikhundleni samagesi kuphela, noma no-T nge-Celsius.