课程名称︰物理化学上 课程性质︰必修 课程教师︰陈振中 开课学院： 开课系所︰农化系 考试日期（年月日）︰2010.12.16 考试时限（分钟）：110 min 是否需发放奖励金：是 （如未明确表示，则不予发放） 试题 : Section A (80%) 1. Ammonia (considered to be an ideal gas) initially at 298 K and 1 bar pressure is heated at constant pressure until the volume have doubled. Calculate (a) q per mole, (b) w per mole, (c) ΔH per mole, (d)ΔU per mole, (e) ΔS per mole. Given: Cp per mole = 25.9 + 33.0*10^(-3)T - 30.46*10^(-7)T^2 in J/K mol. (20%) 2. An ideal monatomic gas is heated from 300 to 1200 K and the pressure is allowed to rise from 1 to 2 bar. What is the change in molar entropy?(10%) 3. At 300 K and a particular pressure, a real gas has a fugacity coefficient φ of 2.50. At this pressure, what is the difference in the chemical potential of this real gas and an ideal gas? (10%) 4. Calculate ΔG and ΔS for mixing 3 mol of hydrogen with 2 mol of oxygen at 25℃ under conditions where no chemical reaction occurs. (10%) 5. Calculate the molar Gibbs energy G of fusion when supercooled water at -5℃ freezes at constant T and P. The enthalpy of fusion of ice is 6000 J/mol at 0℃. The heat capacities of water and ice in the vicinity of freezing point are 75.3 and 38 J/ K mol, respectively.(15%) 6. The NBS tables contain the following data at 298 K : (15%) ΔrH。/ kJ/mol ΔrG。/ kJ/mol CuSO4(s) -771.36 -661.8 CuSO4．H2O(s) -1085.83 -918.11 CuSO4．3H2O(s) -1684.31 -1399.96 H2O(g) -241.818 -228.572 (a)What is the equilibrium constant over a mixture of CuSO4(s) and CuSO4．H2O(s) at 298 K? (b)What is the equilibrium constant over a mixture of CuSO4．H2O(s) and CuSO4．3H2O(s) at 298 K? (c)What is the answer to (a) if the temperature is 400 K and ΔCp。 is assumed to be zero? Section B (20%) 1. (5%)Explain why the reported S298。 value of fluoride ions, F-(ao), is negative. 2. (5%)The Helmholtz energy is defined as A = U - TS. Proove that ╭ δA ╮ S = - │ ————│ ╰ δT ╯V,{ni} (δ 是偏微分) 3. (10%)Consider a system of supercooled water at 263 K. If the system is isolated, predict what would happen after a spontaneous cheange. Explain your prediction with or without calculations. [Hints:you still get marks if you can eliminate some impossible results] You may or may not need the following data: Heat capacity of ice = 36.8 J/ K mol Heat capacity of liquid water = 75.3 J/ K mol Latent heat of fusion at 273 K = -6004J/mol ____________________ U = q+w CdT dS = —— T ___ ___ f G = G。+RTln — p。 ΔG。 = ΔH。- TΔS。 --

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