精華區beta NTU-Exam 關於我們 聯絡資訊
課程名稱︰普通化學丙 課程性質︰必修 課程教師︰黃俊誠 開課學院:生機 農化 昆蟲 開課系所︰生農學院 考試日期(年月日)︰1/19 考試時限(分鐘):200 是否需發放獎勵金:是 (如未明確表示,則不予發放) 試題 : 1. A Sample of an ionic compound NaA, where A- is the anion of a weak aicd, was dissolved in enough water to make 500.0 mL of solution and was then titrated with 0.200M HNO3. After 250.0mL of HNO3 was added, the PH was measured and found to be 4.00. The experimenter found that 500.0mL of 0.200M HNO3 was required to reach the stoichiometric point of the titration. (a) What is the Kb value for A-? (b) Calculare the poh of the solution at stoichiometric point of the titration. 2. You have the following reagents on hand: Solid (pKa of acid form is given) Solution Benzoic acid(4.19) 5.0MHCl Sodium acetate (4.74) 1.0M acetic acid (4.74) Potassium fluoride(3.14) 2.6MNaOH Ammonium chloride(9.26) 1.0M HOCl (7.46) What combinations of reagents would you use to prepare buffers at the following pH values? Please explain your answer? a.3.0 b.4.0 c.5.0 d.7.0 e.9.0 3. Consider a sample containing 10mol of a monoatomic, ideal gas at 27°C and an intial pressure of 10.0atm. Suppose the external pressure is lowered to 1.00 atm in (a) isothermally (b) adiabatic manner. Calculate the final temperature and volume of the gas sample and compute the work for (a) and (b) processes, respectively. 4. Combustion of table sugar produces CO2(g) and H2O(l). When 3.24g of table suger is combusted in constant-volume (bomb) calorimeter, 10.00kJ of heat is liberated. (a) Assuming that table sugar is pure sucrose, C12H22O11 for the combustion reaction. (b) Calculate△E in kJ/mol C12H22O11 for the combustion reaction of sucrose. (c) Calculate △H in kJ/mol C12H22O11 for the combustion reaction of sucrose at 300K. 5. A solution is prepared by miximg 100.0 ml of 1.00*10(-2次) M Mg(NO3)2 and 400ml of 1.00*10(-1次) M NaF. Calculate the concentrations of Mg2+ and F- at equilibrium with solid MgF2 (Ksp=6.4*10(-9次) ). 6. At 100°C and 1.00 atm, △H°=40.6kJ/mol for vaporization of water. Estimate △G° for the vaporization of water at 95°C and 105°. Assume △H°and △S° at 100°C and 1.00atm do not depend on temperature. 7. Cell use hydrolysis of adenosine triphoshpate, abbreviated as ATP, as a soucre of energy. Symbolically, this reaction can be writter as ATP(aq) + H2O(l) --- ADP(aq) + H2PO4- (aq) where AZP represents adenosine diphosphate. For this reaction, △G°=-30kJ/mol. (a) Calculate K at 27°C. (b) If all the free energy from the metabolism of glucose C6H12O6(s) + 6O2(g) --- 6CO2(g) + 6H2O(l) goes into forming ATP from ADP, how many ATP molecules can be produced for every molecule of glucose. 8. For the oxidation-reduction reaction Al(s) + Mn2+ (aq) --- Al3+ (aq) + Mn(s) The appropriate half-reactions are Al3+ + 3e- --- Al E°= -1.18V Balance the redox reaction, and calculate E° and K (at 27°C). 9. For nitrogen gas the values of Cv and Cp at 25°C are 20.8J/K*mol and 29.1 J/K*mol, respectively. When a sample of nitrogen is heated at constant pressure, what fraction of the energy is used to increase the internal the internal energy of the gas? How is the reminder of the energy used? How much energy is required to raise the temperature of 100.0g N2 from 25°C to 75°C in a vessel having a constant volume? 10. A soltion contains 0.5M Ni(NO3)2 and 0.5M Cu(NO)3 . Can the metal ions be separated by slowly adding Na2CO3? Assume that for successful separation 99% of the metal ion must be precipitated before the other metal ion begains to precipate, and assume no volume change on addition of NaCo3. (Ksp for NiCO3=1.4*10(-7次), Ksp for CuCo3 = 2.5*10(-10次) ) 11. Useing the following data, calculate the standard heat of formation of ICl(g) in kJ/mol: Cl2(g) --- 2Cl(g) △H° = 242.3 kJ I2(g) --- 2I(g) △H° = 151.0 kJ ICl(g) --- I(g)+ Cl (g) △H° = 211.3 kJ I2(s) --- I2(g) △H° = 62.8 kJ 12. What is the pH value of water saturated with CO2 at a partial pressure of 1.10 atm at 25°C ? The Henry's law constant for CO2 at 25°C is 3.1*10(-2次) mol/L-atm. The CO2 is acidic oxide, reaction with H2O to form H2CO3. (Ka1 = 4.3*10(-7次) , Ka2 = 5.6* 10(-11次) ) 13. The osmotic pressure of a saturated of strontium sulfate (SrsO4) at 27°C is 21 torr. What is the solubility preduct of this salt at 27°C ? (Ksp of SrSO4 = 3.2*10(-7次) ) 14. 請寫下上完本課程的心得感想或建議。 R = 8.3146 J/K*mol = 0.08206 L*atm/K*mol -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.112.240.126