课程名称︰普通化学丙 课程性质︰必修 课程教师︰郑淑芬 开课学院：医学院 开课系所︰药学系 考试日期（年月日）︰99/12/03 考试时限（分钟）：110分钟 是否需发放奖励金：是 试题内容： Single Choice Questions: (20%, 2 points per question) 1. How many “equivalent” atoms are in a unit cell of body-centered cubic structure? (a) 1 (b) 2 (c) 3 (d) 4 (e) 5 2. Which of the following is polar? (a)SF6 (b) ICl4(-) (c) SF4 (d) AsF6(-) (e) XeF4 3. The molecules OF2 and O3 both have bent shapes. What are the approximate bond angles in OF2 and O3, respectively? (a) 109。 and 120。 (b) both 109。 (c) both 120。 (d) both 180。 (e) 109。 and 180。 4. "Doping" pure silicon with phosphorus results in a _______ material. (a) Ionic conductor (b) n-type semiconductor (c) p-type semiconductor (d) insulator (e) superconductor 5. Which of the following has the highest molar enthalpy of vaporization? (a) Xe (b) LiBr (c)H2O (d) I2 (e) Hg 6. Which of the following substances has the highest boiling point? (a) C2H6 (b) Ar (c) CH2Cl2 (d) HF (e) HCl 7. If the interaction between two species is proportional to 1/r6, which of the following is likely involved? (a) chloromethane molecules in the gas phase (b) chloromethane molecules in the solid phase (c) Li+ and H2O (d) Na+ and H2O (e) Ions in an ionic solid 8. Which of the following are diamagnetic? (a) O2(+) (b) O2(-) (c) N2(2+) (d) N2(2-) (e) O2. 9. Based on their valence-shell electron configurations which of the following species would you expect to have the lowest electron affinity: (a) O2(+) (b) O2(-) (c) O2 (d) N2(+) (e) N2(-). 10. Estimate the value of n for the uppermost filled level in a one-dimensional line of magnesium atoms of length 1.0mm. The radius of a magnesium atom is 160 pm. (a) 6.2*10^6 (b) 3.1*10^6 (c) 1.6*10^6 (d) 7.8*10^5 (e) 3.9*10^5 Descriptive & Calculating Questions 11. Briefly explain the following terms, and give an equation or an example for each of them: (15%) (a) Ferromagnetic (b) Law of Dulong & Petit (c) First law of thermodynamics (d) liquid crystal (e) ionic liquid 12. (a) Sketch the 3s molecular orbitals for a linear (Na)6 where all the Na atoms lie on the z axis. Correlate them with the molecular orbital energy level diagram. (8%) (b) Indicate the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbitals. (2%) 13. Estimate the molar heat capacity (in kJ/mol‧L) of the following gases, considering only the translational and rotational motion, (6%) (a) What is the molar heat capacity at constant pressure of carbon dioxide? (b) What is the molar heat capacity at constant volume of ammonia? 14. A piece of stainless steel (specific heat = 0.652J/g‧℃) is taken from an oven at 238℃ and immersed in 255ml of water (specific heat = 1.00 cal/g‧ ℃) at 24.8℃. The water temperature rises to 53.6℃. What is the mass of the piece of steel? (5%) 15. Calculate the heat required to convert 10.0g of propanol, C3H7OH, from a solid at -150℃ into a vapor at 120℃. The normal melting point and boiling point of C3H7OH are -127℃ and 97℃, respectively. The heat of fusion is 5.18 kJ/mol, and the heat of vaporization is 41.7 kJ/mol. The heat capacities of the solid, liquid and gas states are 142, 170 and 108 J/mol-K, respectively. (5%) 16. Copper metal has a density of 8.92 g/cm^3 and its atomic radius is 128 pm (Atomic weight of Cu= 63.5). (a) Is Cu in a body-centered cubic or face-centered cubic unit cell? (5%) (b) How many copper atoms in a unit cell? (1%) (c) What is the coordination number of the copper atom? (1%) 17. Flausthalite is a mineral composed of PbSe. The mineral adopts a NaCl type structure. The density of PbSe at 25℃ is 8.27 g/cm^3. ( atomic weight: Pb= 207, Se= 79) (a) Calculate the length of an edge of the PbSe unit cell. (5%) (b) Calculate the distance between Pb(2+) and Se(2-) ions in the structure. (3%) 18. (a) Show the molecular orbital energy level diagram for NO. (b) For NO, NO(+), and NO(-), which of them are paramagnetic ? Put them in the order of decreasing the bond length, and account for your answers. (10%) 19. In both the molecule XeOF2 and the ion XeF3(-), a xenon atom is bonded to three other atoms. Please comment on the geometric shapes of these two species and the hybridization of the central xenon atom in each case. (8%) 20. Estimate the standard enthalpy of the following reactions. (a) standard enthalpy of formation of N2O(NNO). (b) H2CCH2 + H2O → CH3CH2OH (c) standard enthalpy of formation of HNO2. Table of Bond enthalpies, KJ/mol ===================================================================== Bond bond enthalpy │ Bond bond enthalpy --------------------------------------------------------------------- H-H 436 │ C-C 348 O=O 496 │ C=C 612 N≡N 944 │ N-N 163 C-H 412 │ N=N 409 N-H 388 │ N-O 210 O-H 463 │ N=O 630 C-O 360 │ C=O 743 ===================================================================== 21. Calculate the ΔU, ΔH, q and w values (in Joule) of isothermal expansion of the ideal gas at 300. K by three different pathways. (15%) (三个Path,图略) Path 1 是两个装有活塞的烧杯(上端有开口)，活塞上放砝码当做下压力。左罐放两个 砝码，P1=8.0atm V1=0.40L 右罐一个砝码 P2=4.0atm V2没给 Path 2 是两个玻璃球，中间以附有开关的细管连接，有两组，第一组的左球里面是充 满气体，右球空，左球P1=8.0atm V1=0.40L，右球V=0.40L。第二组是开关打开，左右两 球皆有气体，V2=V1+V。 Path 3 是两个附有活塞，可抽为真空的罐子(有盖)，活塞上放沙子当作下压力，将活 塞上端抽为真空，下端为气体。左罐沙较多，P1=8.0atm V1=0.40L 右罐沙较少， P2=4.0atm V2没给 Useful information: Gas constant, R= 0.08206 atm Avogadro constant NA= 6.022*10^23/mol Planck’s constant, h= 6.6226*10^34 J.s= 6.626*10^27 erg.s Bolzmann’s constant, k= 1.38066*10^(-23) J/K 1 atm= 760 mmHg = 760 Torr Speed of light, c= 2.9979*10^8 m/s Mass of electron = 9.109*10^(-31) kg Atomic mass: H = 1.00 He= 4.00 C = 12.01 N = 14.01 O = 16.00 F = 19.00 Ne= 20.18 Cl= 35.45 Ar= 39.95 Br= 79.90 I = 126.9 --

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