8. Molecules are known to absorb radiation in which region of the electromagnetic spectrum:
(A) UItraviolet
(B) visible
(C) infrared
(D) microwave
(E) all of the above

4. There is one state at e = O and there are two states at ε = . According to the Boltzmann distribution, the population of second state is 0.15. What is the temperature (K)? (A) 180 K (B) 300K (C) 480 K (D) 90 K (E) ＞ 1000 K

5. The rate constant of a chemical reaction is NOT determined by (A) steric requirement (B) encounter rate (C) minimum energy requirement (D) temperature (E) standard reaction free energy

複選題6. Spherical polar coordinates are used in the solution of the hydrogen atom Schrodinger equation because (A) the Laplacian operator has its simplest form in spherical polar coordinates. (B) Cartesian coordinates would give particle-in-a-box wave functions. (C) the Schrodinger equation is then separable into 3 ordinary differential equations. (D) Otherwise the atomic orbitals would violate the Pauli Exclusion Principle. (E) Schrodinger first used this coordinate system； any other coordinate system would be equally convenient.

7. Consider the thermal decomposition of 1 atm of (CH3)3COOC(CH3)3 to acetone (CH3)2CO and ethane (C2H6), which occurs with a rate constant of 0.02 . After initiation of the reaction, at what time would you expect the pressure to be 2.0 atm? (A) 693 sec (B) 34.65 sec (C) 263 sec (D) 699 sec (E) Can not be determined.

9. The van der Waals equation is expressed as = nRT. Which ofthe following statement is true?(A) Compression factor Z ＜ 1 when a/(RT) ＞ b.(B) Compression factor Z ＜ 1 when a/(RT) ＜ b.(C) Compression factor Z ＜ 1 when a/(RT2) ＜ b.(D) Compression factor Z ＜ 1 when a ＜ b(RT).(E) All of the above is incorrect.

10. Which of the following is "NOT" a correct aspect of the Born-Oppenheimer approximation (A) The electrons in a molecule move much faster than the nuclei. (B) Excited electronic states have the same equilibrium inter-nuclear distance as the ground electronic state. (C) The electronic and vibrational motions of a molecule are approximately (D) Electronic energy curves serve as potential energy functions for nuclear vibrational 3 motions. (E) The typical amplitude of nuclear vibration is much smaller than that characterizing the motion of electrons.

11. The benzene molecule C6H6 has how many vibrational modes (A) 6 (B)12 (C)24 (D)30 (E) 36 separable.

12. For the reaction A + B → product, the reaction rate is first order to A and first order to B. Integrate the rate law. [AJo and [B]o are the initial concentrations for A and B, respectively and [A]o is not equal to [B]o. t = time. (A) (B) (C) (D) (E) All of the above is incorrect. 

13. The normal boiling temperature of ethanol is 78.5℃ and its molar enthalpy change of vaporization at this temperature is 40.3 kJ/mol. Find AU when 3.000 mol of ethanol are vaporized at 78.5℃ at a constant pressure of 1.000 atm. Neglect the volume of the liquid compared with that of the vapor and assume the ethanol vapor as an ideal gas. (A) △U = 120.9 kJ (B) △U = 0.0 kJ (C) △U = -8.77 kJ (D) △U = 130.1 kJ (E) △U= 112.1 kJ

14. The ionization energy for hydrogen atom is 13.6 eV. The ionization Energy for the ground state of is approximately (A)13.6(B)27.2(C)40.8 (D)54.4 (E) 122.4 eV