Kumumanaʻo ʻeleʻele - nā pilikia a me nā hoʻonā
1. 200-gram wai ma 30°C i hui pū ʻia me 100-gram wai ma 90°C. ʻO ka wela kikoʻī o ka wai = 1 cal.gram −1 °C −1 . E hoʻoholo i ka mahana hope loa o ka hui ʻana!
ʻIke ʻia:
Ka nui o ka wai 2 (m1 ) = 200 grams
Mahana o ka wai 1 (T 1 ) = 30 o C
Ka nui o ka wai 2 (m 2 ) = 100 grams
Mahana o ka wai 2 (T 2 ) = 90 o C
ʻO ka wela kikoʻī no ka wai (c) = 1 cal.gram −1 °C −1
Makemake ʻia: Ka mahana hope loa
Lōlā:
Ka wela i hoʻokuʻu ʻia e ka wai anuanu (Q 2 ) = ka wela i omo ʻia e ka wai anuanu (Q 1 )
m 2 c (ΔT) = m 1 c (ΔT)
(100)(1)(90 – T) = (200)(1)(T – 30)
(100)(90 – T) = (200)(T – 30)
9000 – 100T = 200T – 6000
9000 + 6000 = 200T + 100T
15000 = 300T
T = 15000/300
T = 50 ° C
2. 60-gram ma 90 o C i hui pū ʻia me 40-gram wai ma 25 o C. He aha ka mahana hope loa o ka hui ʻana. ʻO ka wela kikoʻī no ka wai = 1 cal.g -1 . o C -1.
ʻIke ʻia:
Ka nui o ka wai 1 (m 1 ) = 60 grams
Mahana o ka wai 1 (T 1 ) = 90 o C
Ka nui o ka wai 2 (m 2 ) = 40 grams
Mahana o ka wai 2 (T 2 ) = 25 o C
ʻO ka wela kikoʻī no ka wai (c) = 1 cal.g -1 . o C -1
Makemake ʻia: Ka mahana hope loa
Lōlā:
Ka wela i hoʻokuʻu ʻia e ka wai anuanu (Q 2 ) = ka wela i omo ʻia e ka wai anuanu (Q 1 )
m 1 c (ΔT) = m 2 c (ΔT)
(60)(1)(90 – T) = (40)(1)(T – 25)
(60)(90 – T) = (40)(T – 25)
5400 – 60T = 40T – 1000
5400 + 1000 = 40T + 60T
6400 = 100T
T = 6400/100
T = 64 ° C
3. Ua hoʻokomo ʻia ka hau M-gram ma 0 o C i loko o ka wai 340-gram ma 20 o C i loko o kahi pahu kikoʻī. ʻO ka wela latent o ka fusion (L hau ) = 80 cal g -1 , ka wela kikoʻī o ka wai (c wai ) = 1 cal g -1 o C -1 . Hoʻoheheʻe ʻia nā hau a pau a ʻo ke kaulike thermal = 5 o C. E huli i ka nuipa o ka hau.
ʻIke ʻia:
Ka nui o ka wai (m) = 340 grams
Mahana o ka hau (T hau ) = 0 o C
Mahana o ka wai (T wai ) = 20 o C
Mahana o ke kaulike wela (T) = 5 o C
Ka wela huna o ka fusion no ka hau (L hau ) = 80 cal g -1
ʻO ka wela kikoʻī no ka wai (c wai ) = 1 cal g -1 o C -1
Makemake ʻia: Nui o ka hau (M)
Lōlā:
Ka wela i hoʻokuʻu ʻia e ka wai (Q 2 ) = ka wela i omo ʻia e ka hau (Q 1 )
m wai c wai (ΔT) = m hau L hau + m hau c wai (ΔT)
(340)(1)(20-5) = M (80) + M (1)(5-0)
(340)(15) = 80M + 5M
5100 = 85M
M = 5100/85
M = 60 grams
4. He keleawe ma 100 o C i hoʻokomo ʻia i loko o 128-gram o ka wai ma 30 o C. ʻO ka wela kikoʻī no ka wai he 1 cal.g -1o C -1 a ʻo ka wela kikoʻī no ke keleawe he 0.1 cal.g -1o C -1 . Inā ʻo ka mahana o ke kaulike wela = 36 o C, he aha ke kaumaha o ke keleawe.
ʻIke ʻia:
Mahana o ke keleawe (T 1 ) = 100 o C
ʻO ka wela kikoʻī no ke keleawe (c 1 ) = 0.1 cal.g -1o C -1
Ka nui o ka wai (m2 ) = 128 grams
Mahana o ka wai (T 2 ) = 30 o C
ʻO ka wela kikoʻī no ka wai (c 2 ) = 1 cal.g -1o C -1
ʻO ka mahana o ke kaulike wela (T) = 36 o C
Makemake ʻia: Nui o ke keleawe ( m1 )
Lōlā:
Q keleawe = Q wai
m 1 c 1 ΔT = m 2 c 2 ΔT
(m 1 )(0.1)(100-36) = (128)(1)(36-30)
(m 1 )(0.1)(64) = (128)(1)(6)
(m 1 )(6.4) = 768
m 1 = 768 / 6.4
m 1 = 120 grams
5. ʻO ke kēpau 3-kg me ka wela kikoʻī no ke kēpau he 1400 J.kg -1 C -1 ma 80 o C i waiho ʻia i loko o ka wai 10-kg me ka wela kikoʻī no ka wai he 4200 J.kg -1 C -1 . ʻO ka mahana o ke kaulike wela he 20 o C. He aha ka mahana mua o ka wai.
ʻIke ʻia:
Ka nuipa o ke kēpau (m1 ) = 3 kg
ʻO ka wela kikoʻī no ke kēpau (c 1 ) = 1400 J.kg -1 C -1
Mahana o ke kēpau (T 1 ) = 80 o C
Ka nui o ka wai (m2 ) = 10 kg
ʻO ka wela kikoʻī o ka wai (c 2 ) = 4200 J.kg -1 C -1
ʻO ka mahana o ke kaulike wela (T) = 20 o C
Makemake ʻia: ʻO ka mahana mua o ka wai (T 2 )
Lōlā:
Hoʻokuʻu Q = omo Q
Q kēpau = Q wai
m 1 c 1 ΔT = m 2 c 2 ΔT
(3)(1400)(80-20) = (10)(4200)(20-T)
(4200)(60) = (42,000)(20-T)
252,000 = 840,000 – 42,000 T
42,000 T = 840,000 – 252,000
42,000 T = 588,000
T = 588,000 / 42,000
T = 14
ʻO ka mahana mua o ka wai he 14 ° C.
6. 75-gram wai ma 0 o C i hui pū ʻia me 50-gram wai no laila ʻo ka mahana o ka hui ʻana he 40 o C. He aha ka mahana mua o ka wai 50-gram.
ʻIke ʻia:
Ka nui o ka wai 1 (m 1 ) = 75 grams
ʻO ka mahana mua o ka wai 1 (T 1 ) = 0 o C
Ka nui o ka wai 2 (m 2 ) = 50 grams
ʻO ka mahana o ka hui ʻana (T) = 40 o C
Makemake ʻia: ʻO ka mahana mua o ka wai 2 (T 2 )
Lōlā:
Ka wela i hoʻokuʻu ʻia e ka wai anuanu ( hoʻokuʻu Q ) = ka wela i omo ʻia e ka wai anuanu (Q absorption )
m 1 c (ΔT 1 ) = m 2 c (ΔT 2 )
m1 ( ΔT1 ) = m2 ( ΔT2 )
(75)(40 – 0) = (50)(T 2 – 40)
(75)(40) = (50)(T 2 – 40)
3000 = 50 T 2 – 2000
3000 + 2000 = 50 T 2
5000 = 50 T 2
T 2 = 100 o C
7. Ua hoʻomehana ʻia ka metala 200-gram i 120 o C, a laila ua kau ʻia i loko o ka wai 100-gram ma 30 o C. ʻO ka mahana o ka hui ʻana ma ke kaulike wela he 60 o C. Inā ʻo ka wela kikoʻī o ka wai he 4200 J.kg -1 o C -1 , he aha ka wela kikoʻī o ka metala.
Lōlā:
E hoʻololi i nā anakahi nuipa mai nā grama i nā kilograma (nā anakahi honua)
ʻIke ʻia:
Ka nuipa o ka metala (m1 ) = 200 grams = 0.2 kg
Mahana o ka metala (T 1 ) = 120 o C
Ka nui o ka wai (m2 ) = 100 grams = 0.1 kg
Mahana o ka wai (T 2 ) = 30 o C
ʻO ka mahana o ka hui ʻana (T) = 60 o C
ʻO ka wela kikoʻī o ka wai (c 2 ) = 4200 J.kg -1 o C -1
Makemake ʻia: Ka wela kikoʻī o ka metala (c 1 )
Lōlā:
Hoʻokuʻu Q = omo Q
m 1 c 1 (ΔT 1 ) = m 2 c 2 (ΔT 2 )
(0.2)(c 1 )(120 – 60) = (0.1)(4200)(60 – 30)
(0.2)(c 1 )(60) = (0.1)(4200)(30)
12 c 1 = 12600
c 1 = 12600 / 12
c 1 = 1050
1. Nīnau: ʻO wai ʻo Joseph Black? Pane: He kauka a he kemika Sekotia ʻo Joseph Black i ke kenekulia 18, i ʻike ʻia no kāna mau ʻike ʻana i ka wela latent, ka wela kikoʻī, a me ke kalapona ʻokikene.
2. Nīnau: He aha ka wela huna? Pane: ʻO ka wela huna ka nui o ka ikehu i omo ʻia a hoʻokuʻu ʻia paha e kahi mea i ka wā o ka loli ʻana o ke ʻano, e like me ka heheʻe ʻana a i ʻole ka paila ʻana, me ka ʻole o ka hoʻololi ʻana i kona mahana.
3. Nīnau: Pehea ka ʻokoʻa o ka wela latent mai ka wela sensible? Pane: ʻOiai ʻo ka wela sensible ke kumu o ka loli ʻana o ka mahana o kahi mea me ka ʻole o ka loli ʻana o ka pae, ʻo ka wela latent ke kumu o ka loli ʻana o ka pae me ka ʻole o ka loli ʻana o ka mahana.
4. Nīnau: He aha ke koʻikoʻi o nā hoʻokolohua a Black ma ka wela latent i ke aʻo ʻana i ka thermodynamics? Pane: Ua hoʻokumu ka hana a Black i ka ʻike kumu o ka ikehu wela a me kona mālama ʻana, e hoʻomākaukau ana i ke ala no nā holomua hou aʻe i ka thermodynamics a me ka calorimetry.
5. Nīnau: No ke aha i ʻokoʻa ai ka nui o ka ikehu wela o ka hau ma 0°C a me ka wai ma 0°C? Pane: Pono ka hau ma 0°C e omo i ka wela latent o ka fusion e lilo i wai ma 0°C. No laila, ʻoi aku ka nui o ka ikehu wela o ka wai ma 0°C ma mua o ka hau ma ka mahana like ma muli o kēia wela latent i omo ʻia.
6. Nīnau: He aha ka wela kikoʻī? Pane: ʻO ka wela kikoʻī ka nui o ka ikehu wela e pono ai e hoʻokiʻekiʻe i ka mahana o kahi anakahi nui o kahi mea ma hoʻokahi kekelē Celsius a i ʻole Kelvin.
7. Nīnau: Pehea i alakaʻi ai ka hana a Black ma ka wela kikoʻī i ka hoʻomaopopo ʻana i nā mana wela like ʻole o nā mea? Pane: Ua ʻike ʻo Black he pono nā nui like o nā mea like ʻole i nā nui like ʻole o ka wela e hoʻokō ai i ka loli like o ka mahana. Ua hoʻolauna kēia nānā ʻana i ke kumumanaʻo o nā mana wela kikoʻī o nā mea.
8. Nīnau: No ke aha he mea nui ka manaʻo o ka wela latent i nā ʻōnaehana aniau? Pane: He kuleana koʻikoʻi ko ka wela latent i nā ʻōnaehana aniau ma muli o ka ikehu e pili ana i nā loli pae o ka wai, e like me ka mahu a me ka condensation. Hoʻopilikia kēia hoʻoili ikehu i ka mahana, ka hoʻokumu ʻia ʻana o ke ao, a me nā ʻano aniau.
9. Nīnau: He aha ka mea hana a Joseph Black i hoʻohana ai e ana i nā loli wela i kāna mau hoʻokolohua? Pane: Ua hoʻohana ʻo Black i kahi calorimeter maʻalahi, kahi mea hana no ke ana ʻana i ka loli wela, i kāna mau hoʻokolohua e helu i ka nui o ka wela i omo ʻia a hoʻokuʻu ʻia paha.
10. Nīnau: Pehea i kōkua ai ka ʻike ʻana o Black i ke kalapona ʻokikene (āna i kapa aku ai he "ea paʻa") i ka kemika? Pane: ʻO ka ʻike ʻana o Black i ke kalapona ʻokikene ma ke ʻano he kinoea ʻokoʻa i ʻokoʻa mai ka ea lewa he mea nui ia i ka holomua o ke kemika kinoea a ua hoʻomākaukau i ke ala no ka hoʻomaopopo ʻana i nā hopena kemika e pili ana i nā kinoea.
