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

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)

18. The change in enthalpy is given by dH = + Vdp. In combination with the Clapeyron equation, find out d(△H/T) and the two phases remain in equilibrium. (A) (B) d(△H/I) = Rd(In T) (C) d(△HIT) =△S d(In T) (D) (E) All of the above is incorrect

19. Which of the following statements about the hydrogen atom ground state is INCORRECT: (A) It is described by the quantum numbers n =1； 1 = 0； m = 0. (B) The electron's angular momentum equals plank constant, h. (C) The wave function is spherically symmetrical. (D) The wave function decreases exponentially as a function of r. (E) The radial distribution function has its maximum at the Bohr radius.

20. At the solid-liquid-vapor triple point of a pure substance, what is the slope, dp/dT of phase transition? (A) solid-vapor line ＞ liquid-vapor line (B) solid-vapor line = liquid-vapor line (C) solid-vapor line ＜ liquid-vapor line (D) solid-vapor line = liquid-vapor line = 0 (E) all of the above is incorrect

21. Based on statistical thermodynamics, which of the following statement about heatcapacity is true?(A) The for Ar is the same as that for Ne, even though the atomic weight of Aris twice that of Ne.(B) The heat capacity for monoatomic atom F is considerably larger than that forNe even though they have about same atomic weight.(C) The heat capacity of liquid water is much larger than that of water vapor.(D) Br2(g) has larger value than that of Cl2(g).(E) The values for the Ar, O2(g), and Cl2(g) are in the order of Cl2(g) ＞ O2(g) ＞Ar.

複選題22. The velocity probability of Maxwell-Boltzmann distribution in one-direction is expressed as: . Which of the following statement about Maxwell- Boltzmann distribution at a finite T is true? (A) The most-probable velocity for a one-dimensional gas velocity distribution is zero. (B) The Maxwell-Boltzmann speed (three dimensions) distribution approaches zero at high speeds. (C) The Maxwell-Boltzmann speed (three dimensions) distribution approaches zero at low speed. (D) The total energy of one mole perfect gas according to the Maxwell-Boltzmann distribution is 1.5RT. (E) Most-probable speed ＞ Mean speed ＞ Root mean square speed.

複選題23. Consider the collision-induced dissociation of N2Os(g) via the following mechanism:  The * symbol in the first reaction indicates the reactant is activated through collision. Experimental ly, it is observed that the reaction can be either first or second order under different conditions. The rate law is expressed as . Which of the following statement is true? (A)m = 2. (B) k'=k1 (C) (D)When , the reaction will be first order in N2O5(g). (E) When , the reaction will be half order in N2O5(g).