※ [本文转录自 NTU-Exam 看板] 作者: youngsam (要加油要加油) 看板: NTU-Exam 标题: [试题] 93上化学系普通化学甲第二次期中考 牟中原陈振中合开 时间: Wed Feb 16 20:11:50 2005 课程名称︰普通化学甲上 班次01(化学系) 课程性质︰必修 课程教师︰牟中原 陈振中合开 开课系所︰化学系 考试时间︰2004.12.3 试题 : 九十三学年度 化学系 普通化学甲 第二次期中考 1. The Ksp of hydroxypatite, Ca5(PO4)3OH, is 6.8X10^-37. Calculate the solubility of hydroxypatite in pure water in moles per liter. How is the solubility of hydroxypatite affected by adding acid? When hydroxypatite is treated with fluride, the mineral flourapatite, Ca5(PO4)3F, forms. The Ksp of this substance is 1X10^-60. Calculate the solubility of fluorapatite in water. How do these calculations provide a reason for the fluoridation of drinking water? 15% 2. Consider a sample containing 2.00mol of a monatomic ideal gas that undergoes the following changes: Pa=10.0atm 1 Pb=10.0atm 2 Pc=20.0atm 3 Pd=20.0atm Va=10.0L → Vb=5.0L → Vc=5.0L → Vd=25.0L For each step, assume that the external pressure is constant and equals the final pressure of the gas for that step. Calculate q, w,and △H for each step and for the overall change from state A to state D. 15% 3. When water is supercooled, it freezes at a temperature below 0.0℃. If 10.9 kJ of heat is released when 2.00mol of supercooled water at -15.0℃ freezes, calculate the molar enthalpy of fusion for ice at 0.0℃ and 1 atm. Assume the molar heat capacities for H2O(s) and H2O(l) are 37.5J/K˙mol and 75.3 J/K˙mol, respectively, and are temperature independent. 15% 4. Calculate the total entropy change when a 2.00 kg mass at 300K falls freely a distance of 25.0m into a heat bath at 300K. 10% 5. Which of the following pairs has greater entropy per mol? (a) Acetone and methane (all in gas phase) (b) Chlorinf and fluorine (all in gas phase) (c) Water and ice at 273K (d) Methane and ethane (all in gas phase) (e) Diamond and graphite 10% 6. Hydrogen for use in the Haber-Bosch process for ammonia synthesis is generated from natural gas by the reaction CH4(g) + H2O(g) → CO(g) + 3H2(g) (a) Calculate △G°for this reaction at 25℃. (b) Calculate Ksp for at 25℃. (c) Is the reaction product-favored under standard conditions? If not, at what temperature will it become so? (d) Estimate Kc for the reaction at 1000K. 20% ┌───────┬────┬────┬────┬────┐ │ │ CH4(g) │ H2O(g)│ CO(g) │ H2(g) │ ├───────┼────┼────┼────┼────┤ │△G°f(kJ/mol)│ -50.22 │-228.572│-137.168│ 0 │ ├───────┼────┼────┼────┼────┤ │△H°f(kJ/mol)│ -74.81 │-241.818│-110.525│ 0 │ ├───────┼────┼────┼────┼────┤ │S°(J/mol˙K) │186.264 │188.825 │197.674 │130.684 │ └───────┴────┴────┴────┴────┘ 7. The molar heat capacity of H2O(g), at constant P, is given by Cp = 30.54 + 0.01T (J/mol˙K) Calculate △S, △H, △E when 100g of H2O at 373K, 1.00atm is heated to 473K, 1.00atm. Assume ideal gas behavior. 15% -- ╭═╮╭╮═══╮═╮╭╮═══╮═══╮═══╮═══╮═╮═╮ ║▌╰╯║▌╭╮║▌║║║▌╭╮║╭╮▌║▌ ╯▌╭╮║▌╧ ║ ╰˙ ╭╯˙╰╯║˙╰╯║˙║║║╰╯˙║˙══╮˙╰╯║˙★╭║ ╰═╯ ═══╯═══╯═╯╰╯═╮ ║═══╯═╯╰╯ ╯ ╰╯ …∵‥∴…∵‥∴…∵‥∴…∵‥∴…╰══╯∵‥∴…∵‥∴…∵‥∴… --

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