課程名稱︰材料熱力學一
課程性質︰必修
課程教師︰林招松
開課學院：工學院
開課系所︰材料系
考試日期（年月日）︰2012/12/5
考試時限（分鐘）：180 分鐘
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
R=8.3144J/(mole K) = 1.987 cal/(mole K) = 0.082057 (liter-atm)/(mole k)
1.Based on the maximum work concept, demonstrate that the work performed by a
system depends on the path linking the initial and final states. (10%)
2. What are the constraints for establishing the equilibrium criterion of a
materials system based on theoretical calculation and experimantal
measuements, respectively ? Reason your answers. (15%)
3. About auxiliary functions
(1) Show that (δS/δV)(定P)=cp/(TVα),where αand cp are the isobaric thermal
expansivity and constant-pressure specific heat capacity of a substance,
respectively. (10%)
(2)Estimate the change in temperature for a poece of alumina at ambient
atmosphere (25度C and 1 atm) when it is loaded to 500Mpa. Note V, α, and
cp are 2.56*10^-5 m^3/mole, 2.2*10^-5 l/K, and 80 J/(mole K), respectively,
for alumina.
(Hint: consider the Maxwell's relationships and the equation shown in problem
3(1)) (10%)
4. A rigid container is divided into two compartment of equal volume by a
partition. One Compartment contains 2 mole of ideal gas A at 2 atm, and the
other contains 1 moles of ideal gas B at 1 atm. Calculate the increase in
entropy which occurs when the partition between the two compartment is
removed. (15%, you will get another 5 extra points if you answer this
question using two different approaches.)
5. About the dependence of heat capacity on temperature
(1) Briefly explain why the Debye model works much better than the Einstein
model at low temperatures, whereas both models predict the same
cv-temperature dependence at high temperatures. (10%)
(2)The atomic weight and melting temperature of some solids are listed in the
following table. Which solid has the largest Debye temperature ? Reason your
answer. (10%)
Solid Atomic weight,g melting temperature, 度C
Ag 107.87 962
Al 26.98 660
Cu 63.55 1085
6.Answer one of the following two questions. (20%)
(1)Calculate the standard enthalpy and entropy changes at 298K for the reaction
2Cu + 1/2O2 = Cu2O ΔG=-40500-3.92TlnT+29.5T cal
(2)Calculate the value of ΔG for the reaction at 600 K.
Si3N4 + 3O2 → 3SiO2(α-quartz) + 2N2
Note:
ΔH(0,298K),J S(0,298K),J/K cp,j/(mole K)
N2 ------- 191.5 27.9+4.3*10^-3 T, 298-2500 K
O2 ------- 205.1 30+4.2*10^-3 T, 298-2500 K
Si3N4 -744800 113.0 76.4+109.0*10^-3 T, 298-900 K
SiO2(α-quartz) -910900 41.5 43.9+38.8*10^-3 T, 298-847 K
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