课程名称︰材料热力学一 课程性质︰必修 课程教师︰林招松 开课学院：工学院 开课系所︰材料系 考试日期（年月日）︰2012/12/5 考试时限（分钟）：180 分钟 是否需发放奖励金：是 （如未明确表示，则不予发放） 试题 : 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 --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 140.112.243.14