複選題

39. Which of the following statements about nuclear reaction and stability are TRUE?
(A) A radioactive nuclide that decays from atoms to 2.5 x 10⁹ atoms in 10.0 mins has a half-life of 5.0 mins.
(B) Nuclides with large Z values are often observed to be a-particle producers.
(C) As Z increases, , nuclides need a greater proton-to-neutron ratio for stability.
(D) Those "light" nuclides that have twice as many neutrons as protons are expected to be stable.
(E) If more than one neutron from each fission event causes another fission event, the fission situation is described as supercritical.

35. The atomic mass is 2.01410 u for . The masses are 0.000549 u for electron, 1.00728 u for proton, and 1.00866 u for neutron. What is the binding energy per nucleon for ? (A) 1.12 MeV(B) 1.42 MeV (C) 2.24 MeV (D) 2.83 MeV (E) 5.66 MeV

複選題36. Consider 150 J of heat added to 40.4 g of Ne in a closed container at 0  ℃ and I atm. If the heat is transferred at constant pressure, which of the following statements are TRUE? (Assume that the gases behave ideally.) (A) The final temperature will increase. (B) The change in enthalpy (△H) is 150 J. (C) The change in internal energy (△E) is 90 J. (D) The work (w) is -60 J. (E) If the heat is transferred at constant volume in the above process, the change in enthalpy (△H) will be 250 J.

37. One mole of an ideal gas undergoes an isothermal reversible expansion at 300 K. During theprocess, the system absorbs 750 J of heat from the surroundings. When this gas iscompressed to the original state in one step isothermally, twice as much work is done on thesystem as was performed on the surroundings in the expansion. Which of the followingstatements are TRUE?(A) for the one-step isothermal compression is 2.5 J/K.(B) for the one-step isothermal compression is 5.0 J/K.(C) for the reversible isothermal expansion is zero.(D) for the overall process (expansion and compression) is zero.(E) for the overall process (expansion and compression) is -2.5 J/K.

38. Consider the standard galvanic cell at 25 ℃ based on the following half-reaction: The electrodes in this cell are Ag(s) and Cu(s). Which of the following changes will make the cell potential decrease? (A) CuSO4(s) is added to the copper half-cell compartment (assume no volume change). (B) NH3(ag) is added to the copper half-cell compartment. (C) NaCl(s) is added to the silver half-cell compartment. (D) Water is added to both half-cell compartments until the volume of solution is doubled. (E) The silver electrode is replaced with a platinum electrode.

複選題40. Which of the following statements about "The Bohr Model" and "Particle in a Box" areTRUE?(A) A function of the type A cos(Lx) can be an appropriate solution for the particle in a one-dimensional box.(B) If the wavelength of light necessary to promote an electron from the ground state to thefirst excited state is λ in a one-dimensional box, then the wavelength of light necessary topromote an electron from the first excited state to the third excited state will be λ/2.(C) The total probability of finding a particle in a one-dimensional box (length is L) in energylevel n = 4 between x = L/4 and x = L/2 is 25%.(D) For an electron trapped in a one-dimensional box, as the length of the box increases, thespacing between energy levels will increase.(E) Assume that a hydrogen atom's electron has been excited to the n = 5 level. When thisexcited atom loses energy, 10 different wavelengths of light can be emitted.

複選題41. Iodine, like most substances, exhibits only three phases: solid, liquid, and vapor. The triplepoint of iodine is at 90 torr and 115 ℃. Which of the following statements concerning liquid I2 are NOT TRUE?(A) I2(I) cannot exit at 1 atmosphere pressure.(B) I2(I) cannot exist above 115℃.(C) I2(I) is denser than I2(g).(D) I2(I) can have a vapor pressure greater than 90 torr.(E) I2(I) cannot exist at a pressure of 10 torr.

複選題42. The following results were obtained at 600 K for the decomposition of ethanol on alumina(Al2O3) surface,Which of the following statements are TRUE?(A) At t = 80 s, is 370 torr.(B) The rate constant is 90 torr/min.(C) This a first order reaction.(D) At t = 300 s, is 700 torr.(E) At t = 100 s, the partial pressure of ethanol is 100 torr.

複選題43. Consider a buffered solution containing CH3NH:Cl and CH3NH2. Which of the followingstatements concerning this solution are TRUE? (A) A solution consisting of 0.10 M CH3NH3CI and 0.10 M CH3NH2 would have a higherbuffering capacity than one containing 1.0 M CH3NH3CI and 1.0 M CH3NH2.(B) If [CH3NH2] ＞ [CH3NH3⁺], then the pH is larger than the pKa value of CH3NH3⁺ .(C) Adding more [CH3NH3Cl] to the initial buffer solution will increase the pH.(D) If [CH3NH2] ＞ [CH3NH3⁺], then pH ＞ 10.50.(E) IF [CH3NH2] = [CH3NH3⁺], then pH = 3.30.

複選題44. Which of the following statements are TRUE? (A) Octahedral complexes are more appropriate than octahedral complexes to be used to determine whether a ligand is a strong-field or a weak-field ligand. (B) The fulminate ions (CNO⁻) can have three different Lewis structures in which all the N atoms have a same formal charge. (C) Cobalt is a component of vitamin B12, which is essential for the metabolism of carbohydrates, fats, and proteins. (D) are all NMR active nuclides. (E) Both Ir(NH3)3Cl3 and [Ni(H2O)+(NO2)2] exhibit geometric isomerism.

複選題45. Consider 1.0 mole of a monatomic ideal gas in a container fitted with a piston. The initialconditions are V = 5.0 L and P = 4.0 atm at some constant T. These two processes areperformed isothermally:(a) The external pressure is suddenly changed to 2.0 atm to allow expansion of the gas.(b) Followed by process (a), the external pressure suddenly changes back to 4.0 atm tocompress the gas.Which of the following statements about these two processes are NOT TRUE?(A) In process (a), expansion of the gas is spontaneous.(B) In process (b), compression of the gas is nonspontaneous.(C) The sign of free energy change (△G) can be used to predict spontaneity of these twoprocesses.(D) In process (a), the change of internal energy (△E) is zero during the gas expansion.(E) In process (b), the sign of is negative during the gas compression.