Ukushisa nokushintsha kwesigaba - izinkinga nezixazululo

Ukushisa nokushintsha kwesigaba - izinkinga nezixazululo

1. Ngokusekelwe kugrafu, kuyini ukushisa okumuncwa amanzi angu-5 kg ​​ngesikhathi senqubo ye-CD? Ukushisa okuqondile kwamanzi = 4,200 J/kg ^o C.

Kwaziwa:

Isisindo (m) = 5 kg

Ukushisa kwamanzi okuqondile (c) = 4200 J/kg ^o C

Izinga lokushisa lokuqala (T ₁ ) = 0 ^o C

Izinga lokushisa lokugcina (T2 ₎ = 10 ^o C

Ushintsho lokushisa (ΔT) = 10 ^o C – 0 ^o C = 10 ^o C

Okufunwayo: Ukushisa (Q)

Isixazululo:

Q = mc ΔT = (5 kg)(4200 J/kg ^o C)(10 ^o C) = (5)(4200 J)(10) = (50)(4200 J) = 210,000 Joules

2. Kuyini ukushisa okumuncwa amagremu angu-20 eqhwa ngesikhathi senqubo ye-AC, uma ukushisa kweqhwa elithile kungu-2100 J/kg ^oC futhi ukushisa kokuhlanganiswa kweqhwa kungu-336,000 J/kg.

Kwaziwa:

Isisindo seqhwa (m) = 200 amagremu = 200/1000 amakhilogremu = 0.2 amakhilogremu

Ukushisa okuqondile (c) = 2100 J/kg ^o C

Ukushisa kokuhlanganiswa kweqhwa (L _F ) = 336,000 J/kg

Kufunwa: Ukushisa kumuncwa yiqhwa ngesikhathi senqubo ye-AC

Isixazululo:

Ngesikhathi senqubo i-AB, ukushisa kumuncwa yiqhwa ukushintsha izinga lokushisa kusuka ku--10 ^o C kuya ku-0 ^o C.

Q = mc ΔT

Q = ukushisa, m = isisindo seqhwa, c = ukushisa okuthile kweqhwa, ΔT = ushintsho lokushisa

Q ₁ = mc ΔT = (0.2)(2100)(0-(-10) = (0.2)(2100)(10) = (2)(2100) = 4200 ama-Joules

Ngesikhathi senqubo ye-BC, ukushisa kuyamuncwa ukuze kuncibilikiswe lonke iqhwa libe ngamanzi. Kule nqubo kushintsha kuphela esigabeni futhi akukho shintsho ekushiseni. Izinga lokushisa leqhwa namanzi lihlala lingu-0 ^o C.

Ukushisa kumuncwa ngesikhathi senqubo ye-BC:

Q ₂ = m L _F = (0.2 kg)(336,000 J/kg) = 67,200 Joules

Ukushisa kumuncwa ngesikhathi senqubo ye-AC:

Q = Q ₁ + Q ₂ = 4200 Joules + 67,200 Joules = 71,400 Joules

3. Amanzi angu-2 kg ayashiswa, kanti ukushisa kokuhwamuka kwamanzi = 2.27 x 10 ⁶ J/kg, ukushisa okuthile kwamanzi = 4,200 J/kg ^o C kanti ingcindezi yomoya ingu-1 atm, kuyini ukushisa okumuncwa amanzi ngesikhathi senqubo BC?

Kwaziwa:

Isisindo (m) = 2 kg

Ukushisa kokuhwamuka kwamanzi (L _V ) = 2.27 x 10 ⁶ J/kg

Ukushisa okuqondile kwamanzi (c) = 4,200 J/kg ^o C

Okufunwayo: Ukushisa kumuncwa ngesikhathi senqubo BC.

Isixazululo:

Enqubweni ye-AB, ukushisa kuyamuncwa ukuze kwandiswe izinga lokushisa lamanzi kusuka ku-60 ^o C kuya ku-100 ^o C.

Q = m L _V = (2 kg)(2.27 x 10 ⁶ J/kg) = 4.54 x 10 ⁶ AmaJoules = 4540 x 10 ³ AmaJoules = 4540 kilo

4. Ngokusekelwe esithombeni esingezansi, uma isisindo seqhwa singamagremu angu-500, ukushisa okuthile kungu-2100 J/kg ^oC kanye nokushisa okucashile kokuhlanganiswa kweqhwa kungu-336,000 J/kg. Thola ukushisa okudingekayo enqubweni P–Q–R.

Kwaziwa:

Isisindo seqhwa (m) = 500 amagremu = 500/1000 kg = 0.5 kg

Ukushisa okuqondile kweqhwa (c) = 2100 J/kg ^o C

Ukushisa okucashile kokuhlanganiswa (L _F ) = 336,000 J/kg

Okufunwayo: Ukushisa

Isixazululo:

Inqubo PQ = ukushisa okumuncwayo ukuze kukhushulwe izinga lokushisa leqhwa kusuka ku--4 ^o C kuya ku-0 ^o C

Inqubo QR = ukushisa okumuncwa yiqhwa ukuze kuncibilikiswe lonke iqhwa emanzini

Ukushisa kuthathwe ngesikhathi senqubo ye-PQ kubalwa kusetshenziswa i-equation:

Q = mc ΔT

Q = ukushisa, m = isisindo, c = ukushisa okuqondile kweqhwa, ΔT = ushintsho lokushisa

Iqhwa elimuncwa ukushisa ngesikhathi senqubo ye-PQ libalwa kusetshenziswa lesi sibalo:

Q = (0.5 kg)(2100 J/kg ^o C)(0 ^o C-(-4 ^o C))

Q = (0.5 kg)(2100 J/kg ^o C)(0 ^o C + 4 ^o C)

Q = (0.5 kg)(2100 J/kg ^o C)(4 ^o C)

Q = (0.5)(2100 J)(4)

Q = 4200 Joule

Ukushisa kuthathwe ngesikhathi senqubo ye-QR kubalwa kusetshenziswa lesi sibalo:

Q = m L _F

Q = (0.5 kg)(336,000 J/kg)

Q = (0.5)(336,000 J)

Q = 168,000 Joule

Ukushisa okuphelele:

Q = 4200 Joules + 168,000 Joules

Q = 172,200 Joule

Q = 172.2 kilogram Joule

Q = 172.2 kJ

5. Iqhwa elinobunzima obungamagremu angu-50 elishiswa kusukela ku--5 ^° C liye emanzini ku-60 ^° C. Uma ukushisa kokuhlanganiswa kweqhwa kungu-80 cal/gram, ukushisa okuqondile kweqhwa kungu-0.5 cal/gram ^oC , ukushisa okuqondile kwamanzi kungu-1 cal/gram ^oC , nquma ukushisa okudingekayo ku-CD yenqubo.

Kwaziwa:

Isisindo seqhwa = isisindo samanzi (m) = amagremu angu-50

Ukushisa okucashile kokuhlanganiswa kweqhwa (LF ₎ = 80 cals/gram

Ukushisa okuqondile kweqhwa (c ice) = 0.5 cal/gram ^o C

Ukushisa okuqondile kwamanzi (c amanzi) = 1 cal/gram ^o C

Kufunwa: Ukushisa kuyadingeka kwi-CD yenqubo

Isixazululo:

Enqubweni A kuya ku-B, ukushisa kusetshenziswa ukuphakamisa izinga lokushisa leqhwa kusuka ku--5 ^o C kuya ku-0 ^o C. Ukushisa kubalwa kusetshenziswa lesi sibalo: Q = mc ΔT, lapho u-Q = ukushisa, m = isisindo seqhwa, c = ukushisa okuthile kweqhwa, u-ΔT = ushintsho lokushisa kusuka ku--5 ^o C kuya ku-0 ^o C.

Enqubweni B kuya ku-C, ukushisa kusetshenziswa ukuncibilikisa lonke iqhwa libe ngamanzi. Kule nqubo, izinga lokushisa alishintshi. Ukushisa kubalwa kusetshenziswa lesi sibalo: Q = m L _F , lapho Q = ukushisa, m = isisindo seqhwa, L _F = ukushisa okucashile kokuhlanganiswa kweqhwa.

Enqubweni C kuya ku-D, ukushisa kusetshenziswa ukuphakamisa izinga lokushisa lamanzi kusuka ku-0 ^o C kuya ku-60 ^o C. Ukushisa kubalwa kusetshenziswa lesi sibalo: Q = mc ΔT, lapho u-Q = ukushisa, m = isisindo samanzi, c = ukushisa okuthile kwamanzi, ΔT = ushintsho lokushisa kusuka ku-0 ^o C kuya ku-60 ^o C.

Ukushisa okudingekayo kusukela kunqubo C kuya ku-D:

Q = mc ΔT = (50 gram)(1 cal/gram ^o C)(60 ^o C-0 ^o C) = (50)(1)(60) cal = 3000 cal

6. Uma isisindo seqhwa singu-1 kg, ukushisa okuqondile kweqhwa kungu-2100 J/kg ^o C, ukushisa okucashile kokuhlanganiswa kweqhwa kungu-336,000 J/kg kanye nokushisa okuqondile kwamanzi kungu-4200 J/kg ^o C, bese unquma ukushisa okudingekayo enqubweni ye-PQR.

Kwaziwa:

Isisindo seqhwa = 1 kg

Ukushisa okucashile kokuhlanganiswa kweqhwa (L _F ) = 336,000 J/kg

Ukushisa okuqondile kweqhwa (c ice) = 2,100 J/kg ^o C

Ukushisa kwamanzi okuqondile (c amanzi) = 4,200 J/kg ^o C

Kudingeka: Ukushisa kuyadingeka enqubweni ye-PQR

Isixazululo:

Enqubweni P kuya ku-Q, ukushisa kusetshenziswa ukuphakamisa izinga lokushisa leqhwa kusuka ku--5 ^o C kuya ku-0 ^o C. Ukushisa kubalwa kusetshenziswa lesi sibalo: Q = mc ΔT, lapho Q = ukushisa , m = isisindo seqhwa , c = ukushisa okuthile kweqhwa, ΔT = ushintsho lokushisa kusuka ku --5 ^o C kuya ku -0 ^o C.

Ukushisa kuyadingeka enqubweni P kuya ku-Q:

Q = mc ΔT = (1)(2100)(0-(-5)) = (2100)(5) = 10500 amaJoules

Enqubweni ethi Q kuya ku-R, ukushisa okudingekayo ukuze kuncibilikiswe lonke iqhwa emanzini. Kule nqubo, izinga lokushisa alishintshi. Ukushisa kubalwa kusetshenziswa lesi sibalo: Q = m L _F , lapho Q = ukushisa , m = isisindo seqhwa , L _F = ukushisa okucashile kokuhlanganiswa kweqhwa.

Ukushisa kuyadingeka enqubweni Q kuya ku-R:

Q = m L _F = (1)(336,000) = 336,000 Joules

Ukushisa okuphelele:

10,500 + 336,000 = 346,500 amaJoules

1. Kuyini ukushisa okucashile?
   • Impendulo: Ukushisa okucashile amandla okushisa adingekayo ukushintsha isigaba sento ngaphandle kokushintsha izinga lokushisa layo. Kumelela amandla adingekayo ukuphula noma ukwakha izibopho eziphakathi kwama-molecule ngesikhathi sokushintsha kwesigaba.
2. Kungani izinga lokushisa lihlala lingaguquki ngesikhathi sokushintsha kwesigaba?
   • Impendulo: Ngesikhathi sokushintsha kwesigaba, wonke amandla okushisa anikeziwe noma asusiwe asetshenziselwa ukushintsha isigaba sento. Lawa mandla asetshenziselwa ukuphula noma ukwakha izibopho eziphakathi kwama-molecule, hhayi ukwandisa amandla e-kinetic noma izinga lokushisa lento.
3. Uyini umehluko phakathi kokushisa okufihliwe kokuhlanganiswa nokushisa okufihliwe kokushisa komoya?
   • Impendulo: Ukushisa okucashile kokuhlanganiswa kubhekisela emandleni okushisa adingekayo ukushintsha into kusuka kokuqinile kuya kokumanzi (noma okuphambene nalokho) endaweni yayo yokuncibilika. Ukushisa okucashile kokuhwamuka kubhekisela emandleni okushisa adingekayo ukushintsha into kusuka kokumanzi iye kugesi (noma okuphambene nalokho) endaweni yayo yokubila.
4. Kungani sizizwa sibanda uma siphuma echibini lokubhukuda ngosuku olunomoya, noma ngabe izinga lokushisa lomoya lifudumele?
   • Impendulo: Njengoba amanzi ephuma esikhumbeni sethu, ashintsha ngokwesigaba kusukela koketshezi kuya komswakama. Le nqubo idinga amandla, athathwa esikhumbeni sethu ngesimo sokushisa, okwenza isikhumba sethu sizizwe sipholile.
5. Kungani umusi okushisa ku-100°C uyingozi kakhulu kunamanzi abilayo ku-100°C?
   • Impendulo: Umusi unamandla amaningi kunamanzi abilayo ngoba umunce ukushisa okucashile kokuhwamuka ngesikhathi sokushintsha kwesigaba kusuka emanzini kuya kumusi. Lapho umusi uhlangana esikhumbeni, ukhipha la mandla engeziwe, okubangela ukusha okukhulu kunamanzi abilayo.
6. Ukwengeza usawoti eqhweni kunciphisa kanjani izinga lokuncibilika kwalo?
   • Impendulo: Ukwengeza usawoti kuphazamisa ukulingana phakathi kokuncibilika nokuqandisa kwengxube yamanzi eqhwa. Lokhu kubangela ukuthi iqhwa eliningi lincibilike ekushiseni okuphansi kunokuvamile, okwehlisa ngempumelelo izinga lokubanda kwengxube.
7. Kungani ukujuluka kusiza ekupholiseni umzimba ngosuku olushisayo?
   • Impendulo: Ukujuluka, uma kuphuma esikhumbeni, kushintshashintsha isigaba kusuka koketshezi kuya kugesi. Le nqubo yokuhwamuka idinga amandla, athathwa esikhumbeni, ngaleyo ndlela kusipholise.
8. Kuyini i-sublimation kumongo wezinguquko zesigaba?
   • Impendulo: I-Sublimation ukushintsha kwesigaba okuqondile kusuka kokuqinile kuya kugesi ngaphandle kokudlula esigabeni soketshezi. Isibonelo esivamile iqhwa elomile (i-carbon dioxide eqinile) eliguqukela ngqo kugesi we-carbon dioxide.
9. Kungani kudingeka amandla okushisa ukuze kuncibilikiswe iqhwa yize izinga lokushisa lihlala liyi-0°C?
   • Impendulo: Amandla okushisa asetshenziselwa ukuphula izibopho eziphakathi kwama-molecule ezibambe iqhwa esakhiweni salo esiqinile. Uma lezi zibopho seziphukile, iqhwa lishintshela esigabeni soketshezi, yize kungekho shintsho ekushiseni.
10. Ukucindezela kuthinta kanjani izinga lokubila koketshezi?

• Impendulo: Ngokuvamile, ukwandisa ingcindezi yangaphandle kuphakamisa iphuzu lokubila loketshezi, kuyilapho ukunciphisa ingcindezi kunciphisa iphuzu lokubila. Yingakho amanzi ebila emazingeni okushisa angaphansi kuka-100°C ezindaweni eziphakeme, lapho ingcindezi yomoya iphansi khona.