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

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.

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

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.

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

15. Which of the following is NOT a correct consequence of the Heisenberg Uncertainty principle: (A) The shorter the lifetime of an excited state of an atom, the less accurately can its energy be measured. (B) An electron in an atom cannot be described by a well-defined orbit. (C) The momentum of an electron cannot be measured exactly. (D) Measurement of one variable in an atomic system can affect subsequent measurements of other variables. (E) A harmonic oscillator possesses a zero-point energy.

16. The Joule coefficient, u, is defined as . a is the thermal expansion coefficient. is the isothermal compressibility. Which of the following equation is correct? (A)(B) (C) (D) (E)

17. The orbital degeneracy (excluding spin) of hydrogen atom energy levels equals (A)n-1(B)n(C)n+1(D) 2n+1(E)n2