所屬科目:研究所、轉學考(插大)◆物理化學及分析化學
1. At a particular temperature, the half-life of a zero-order reaction is 29.0min. How long will it take for the reactant concentration to be depleted by a factor of 8 ([A]t/[A]0 = 1/8)? (A) 87.0min (B) 58.0min (C) 50.8min (D) 232min (E) 203min
2. Consider the reaction: 2SO2(g) + O2(g) ⇌ 2SO3(g), for which ΔH° = −200. kJ and ΔS° = −187 J/K at 25°C. Assuming that ΔH° and ΔS° are independent of temperature, calculate the temperature where Kp = 1. (A) 200 K (B) 1070 K (C) 2070 K (D) 970 K (E) none of these
3. Which of the following statements is/are true of adiabatic process?1. In an adiabatic process, no energy such as heat flows into or out of the system. 2. An adiabatic process occurs when a system is thermally conducted to the surroundings.3. For an adiabatic process, q = 0 and ΔE = w. (A) 1 only (B) 2 only (C) 3 only (D) 1 and 2 (E) 1 and 3
4. Which occupied orbital has the highest energy in the rubidium atom at ground state? (A) 4p (B) 4s (C) 5s (D) 1s (E) 4d
5. The rate constant for a reaction increases from 10.0 s⁻¹ to 100. s⁻¹ when the temperature is increased from 315K to 416K. What is the activation energy for the reaction in kJ/mol? (R = 8.314 J/mol·K) (A) 10.8 kJ/mol (B) 0.0823 kJ/mol (C) 1.90 kJ/mol (D) 19.3 kJ/mol (E) 24.8 kJ/mol
6. How many of the following electron configurations for the species in their ground state are correct? Ca 1s²2s²2p⁶3s²3p⁶4s² Mg 1s²2s²2p⁶3s¹ V [Ar] 3s²3d³ As [Ar] 4s²3d¹⁰4p³ P 1s²2s²2p⁶3p⁵ (A) 1 (B) 2 (C) 3 (D) 4 (E) 5
7. The elementary chemical reaction O + ClO → Cl + O2 is made pseudo-first order in oxygen atoms by using a large excess of ClO radicals. The rate constant for the reaction is 3.5 × 10⁻¹¹ cm³/molecule·s. If the initial concentration of ClO is 1.0 × 10¹¹ molecules/cm³, how long will it take for the oxygen atoms to decrease to 10.% of their initial concentration? (A) 3.2 × 10⁻³ s (B) 0.66 s (C) 0.017 s (D) 23 s (E) 2.4 s
8. Which following quantum model is most adequate as an approximation to describe an p electron moving in benzene? (A) A particle in a one-dimensional box. (B) Harmonic oscillator. (C) A freely moving particle. (D) Rotation in two dimensions. (E) A particle in a two-dimensional box.
9. Consider the second-order reaction aA → products (which has a first half-life of 25 s). If the concentration of A after 15.6 s is 0.36 M, determine the initial concentration of A. (A) 0.58 M (B) 0.26 M (C) 0.53 M (D) 0.14 M (E) 0.16 M
10. For an electron in a 2.00-nm one-dimensional box, calculate the wavelength of electromagnetic radiation to excite the electron from the ground state to the level with n = 3. (A) 140 pm (B) 467,000 nm (C) 32 mm (D) 1,650 nm (E) 62 fm
11. For the vaporization of water at 1.00 atm, ΔH = 43.54 kJ/mol at 298 K and ΔH = 40.68 kJ/mol at 373 KThe constant-pressure heat capacity of liquid water is 75.3 J/mol·K. Calculate the constant-pressure heat capacity for H2O(g). (A) 20.8 J/mol·K (B) 2790 J/mol·K (C) 75.3 J/mol·K (D) 37.2 J/mol·K (E) none of these
12. Which of the following is true for ΔSsurr and ΔSsys, changes of entropy for surrounding and system, respectively? (A) For any process, ΔSsurr and ΔSsys have opposite signs. (B) As long as the disorder of the surroundings is increasing, a process will be spontaneous. (C) If ΔSsurr = −ΔSsys, the process is at equilibrium. (D) ΔH° is zero for a chemical reaction at constant temperature. (E) none of these
13. The density of the solid phase of a substance is 0.9 g/cm³ and the density of the liquid phase is 1.0 g/cm³. A large increase in pressure will (A) Lower the freezing point. (B) Raise the freezing point. (C) Lower the boiling point. (D) Raise the triple point. (E) Lower the triple point.
14. Light emitted from a redox reaction at an electrode is called: (A) photoluminescence (B) bioluminescence (C) chemiluminescence (D) electrochemiluminescence
15. The term laser is an acronym for light amplification by stimulated emission of radiation. What is the basis of laser behavior that causes emission totally coherent with the incoming radiation? (A) pumping (B) spontaneous emission (C) stimulated emission (D) absorption
16. What kind of optical filter can be utilized to reject a specific wavelength? (A) edge filter (B) interference filter (C) notch filter (D) cut-off filter
17. The ability of a monochromator to separate different wavelengths depends on its dispersion. The angular dispersion is given by dr/dλ, where dr is the change in angle of reflection or refraction with a shift in wavelength dλ. In contrast, the linear dispersion D refers to the variation in wavelength as a function of y, the distance along the focal plane. If the distance between rulings decreases the linear dispersion would be: (A) increased (B) decreased (C) unrelated (D) both take place by chance
18. Which monochromator listed below provides better resolution with similar light-gathering power? (A) prism (B) Echelle grating (C) Echellette grating (D) holographic gratings
19. To determine which photon transducer offers the best sensitivity in the 1000-1500 nm range, which of the following transducers give the best sensitivity? (A) photomultiplier tube (B) GaAs photovoltaic cell (C) PbS photoconductivity (D) CdS photoconductivity
20. For a compound with Raman activity of a given vibrational mode, scattering occurs owing to change of: (A) dipole moment (B) electronegativity (C) electron affinity (D) polarizability
21. A unique feature of capillary electrophoresis is electroosmotic flow (EOF). When a high-voltage is applied across a fused-silica capillary tube containing a buffer solution, electroosmotic flow usually occurs, in which the bulk liquid migrates toward the cathode. What is the polarity of EOF in the presence of chemical modification (cetyltrimethylammonium bromide, CTAB) on the capillary wall? (A) positive (B) negative (C) neural (D) bipolarity
1. The efficiency of chromatographic columns can be approximated by van Deemter equation: Explain why the Cs (or CM) affect the plate height?