课程名称︰普通化学(丙) 课程性质︰系定必修 课程教师︰黄俊诚 开课学院：生农学院 开课系所︰园艺系 考试日期（年月日）︰ 2008/4/17 考试时限（分钟）： 120 是否需发放奖励金：是 （如未明确表示，则不予发放） 试题 : 1. Nomenclature: Name or write the formula of each of the following compounds: CO, HCl, NaHCO3, ammonium perchlorate, hypochlorous acid, laughing gas, lead(II) acetate. 2. The enthalpy of the formation of cesium bromide is Cs(s) + 1/2 Br2(l) → CsBr(s) △Hf = -406kJ The first and the second ionization energy of cesium gas are 376 and 2234 kJ/mol, respectively. The ionization energy of bromine atom(gas) is 1140kJ/mol. The enthalpy of sublimation of cesium is 76.1kJ/mol, and the electron affinity of it is 45.5kJ/mol The bond energy of Br2(g) is 111.9kJ/mol, and the electron affinity of Br(g) is -27kJ/mol. The enthalpy of vaporization of liquid bromide is 30.9kJ/mol. Please calcaulate the lattice energy of CsBr(s). 3. Write the expected electron configuration for P, Br^(-1), Fe^(2+), Ar and O^(2-) 4. Calaulate the intermolecular collision frequency and the mean free path for an oxygen molecule in a sample of pure oxygen gas at 127 degree celsius and 0.01 atm. Assume the diameter of an O2 molecule is 0.3nm. 5. Molecule structure: (i)SO3, (ii)IF3, (iii) KrBr4, (iv) SF4 a. Write the most stable Lewis structure of them and explain your answer b. Assign the formal charge to each central atom of them. c. Predict these molecule structures. (VSEPR) d. Please give the expected hybrid orbitals for the central atoms. 6. Which of the following statements is(are) true? For the false statements, correct them. (a) For H2(g) and CO2(g) are in ideal gas condition, the average kinetic energy of C)2 is larger than that of H2 at constant temperature. (b) A real gas behaves most ideally when the container volume is relatively large and the gas molecule size is small. (c) Following (a), H2(g) behaves more ideally than CO2(g) at low pressure and high temperature. (d) The kinetic molecular theory predicts that the intermolecular collisions (frequency) are proportional to the temperature and the molar mass. (e) Following (d), the collisions rate(Za) is inversely proportional to the average velocity and the number of the gas particles. 7. Many biochemical reactions are catalyzed by large protein molecules called enzymes. A typical mechanism for the conversion od a biochemical substrate (S) to a product(P) catalyzed by an enzyme(E) involvesthe following steps: k1 E + S → ES ← k-1 k2 ES → P The rate-determining step is the decomposition of the intermediate enzyme- substrate complex (ES) to products(P). Under these conditions, show that the overall rate of product formation is: d[P] k2[E]t[S] k-1 + k2 Rate = －－ = —————— Km = ————— dt Km + k1[S] k1 where [E]t equals the toal enzyme concentrations: [E]t = [E] + [ES] 8. In 1990, the remains of an apparently prehistoric man were found in a melti- ng glacier in Italian Aps. Analysis of the 14C content of sample of wood from his tools gave a decay rate of 7.5 dpm/g carbon. How long age did the man die?(14C/12C ratio in living organism is 1.3*10^-12, a decay rate of 15 dpm per gram of carbon and half life of 14C is 5700 years.) (dpm: disintegration per minute) 9. Which of the following statements is(are) true? For the false statements, correct them. (a) All bonding molecular orbitals(MOs) are lower in energy than atomic orbitals of which they are composed. (b) Electrons are never found in an antibonding MO. (c) A triple bond is composed of one σ bond and two π bonds. (d) B2 and N2 are diamagnetic and O2+ is paramagnetic. (e) follwing (d), the bond order of B2 and O2+ are both 2. (f) The size arrangement of a seris of isoelectronic ions is S^(2-) < Cl^(-) < K^(+) < Ca^(2+). 10. The decomposition of NH3 to N2 and H2 was studied on two surfaces. Surface Ea(kJ/mol) W 163 Os 197 Without a catalyst the activation energy is 335 kJ/mol. a. Which surface is the better heterogeneous catalyst for the decomposition of NH3? b. How many times faster is the reaction at 298K on the W surface compared with the reaction with no catalyst present? △ 11. A reaction is : H2(g) + CO2←→CO(g) + H2O(g) (endothermic) How will the equilibrium position shift in each of the following cases? a. Gaseous carbon dioxide is removed. b. Water vapor is added. c. The pressure is increased by adding nitrogen gas. d. The temperature is increased. e. The pressure is increased by decreaseing the volume of the cotainer. 12. Lexan is a plastic used to make compact discs, eyelass lenses, and bullet- proof glass. One of the compound used to make Lexan is phosgene(COCl2), a poisonous gas. Phosgene is product by the reaction: CO(g) + Cl2(g) ←→ COCl2(g) For which Kp = 1,5*10^8 atm^(-1) at 100 degree Celsius, calculate Kc at this temperature. * R = 0.08206 L*atm*mol^(-1)*K^(-1) = 8.3145 J*mol^(-1)*K^(-1) --

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