The following information is given for tin at 1atm:
boiling point = 2.270×103 °C Hvap(2.270×103 °C) = 1.939×103 J/g
melting point = 232.0 °C
Hfus(232.0 °C) = 59.60 J/g
specific heat solid = 0.2260 J/g°C
specific heat liquid = 0.2430 J/g°C
A 41.90 g sample of solid tin is initially at 219.0 °C. If the sample is heated at constant pressure (P = 1 atm),________
kJ of heat are needed to raise the temperature of the sample to 453.0 °C.
Chem101 Heat Transfer?
2016-03-02 1:42 am
回答 (2)
2016-03-02 2:17 am
On raising temperature: Heat = m c ΔT
On changing state: Heat = m L
Heat needed to raise the temperature of solid tin from 219.0°C to 232.0°C
= 41.90 × 0.2260 × (232.0 - 219.0) / 1000 kJ
= 0.1231 kJ
Heat needed to melt the solid tin at 232.0°C
= 41.90 × 59.60 / 1000 kJ
= 2.497 kJ
Heat needed to raise the temperature of liquid tin from 232.0°C to 453°C
= 41.90 × 0.2430 × (453.0 - 232.0) / 1000 kJ
= 2.250 kJ
Total heat needed
= 0.1231 + 2.497 + 2.250 kJ
= 4.870 kJ
On changing state: Heat = m L
Heat needed to raise the temperature of solid tin from 219.0°C to 232.0°C
= 41.90 × 0.2260 × (232.0 - 219.0) / 1000 kJ
= 0.1231 kJ
Heat needed to melt the solid tin at 232.0°C
= 41.90 × 59.60 / 1000 kJ
= 2.497 kJ
Heat needed to raise the temperature of liquid tin from 232.0°C to 453°C
= 41.90 × 0.2430 × (453.0 - 232.0) / 1000 kJ
= 2.250 kJ
Total heat needed
= 0.1231 + 2.497 + 2.250 kJ
= 4.870 kJ
2016-03-02 2:15 am
Heat required to raise sample to melting point:
q = m c (T2-T1)
q = 41.90 g (0.2260 J/gC) (232.0 - 219.0) = 123.1 J
Heat required to melt sample:
q = 41.90 g (59.60 J/g) = 2497 J
Heat required to raise temp of liquid tin to desired temperature:
q = m c (T2-T1)
q = 41.90 g (0.2430 J/gC) (453.0 - 232.0) = 2250 J
Total = 2250 + 2497 + 123 J = 4870 J = 4.870 kJ
q = m c (T2-T1)
q = 41.90 g (0.2260 J/gC) (232.0 - 219.0) = 123.1 J
Heat required to melt sample:
q = 41.90 g (59.60 J/g) = 2497 J
Heat required to raise temp of liquid tin to desired temperature:
q = m c (T2-T1)
q = 41.90 g (0.2430 J/gC) (453.0 - 232.0) = 2250 J
Total = 2250 + 2497 + 123 J = 4870 J = 4.870 kJ
收錄日期: 2021-04-18 14:38:27
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160301174235AAenwEX