複選題
61. A solution contains the ions Ag⁺ , Ba²⁺, and Ni²⁺. Dilute solutions of NaCl, Na₂SO₄, and Na₂S are available to separate the positive ions from each other. In order to effect separation, the solutions should be added in which order?
(A) Na₂S, NaCl, Na₂SO₄
(B) Na₂SO_4, NaCl, Na₂S
(C) Na₂SO₄, Na₂S, NaCl
(D) NaCl, Na₂S, Na₂SO₄
(E) NaCl, Na₂SO₄, Na₂S

27. The following reaction takes place at 120 °C: H2O(l) → H2O(g) , ΔH = 44.0 kJ/mol, ΔS = 0.119 kJ/mol·K. Which of the following must be true? (A) The reaction is not spontaneous. (B) The reaction is spontaneous. (C) ΔG < 0 (D) Two of these. (E) None of the above.

28. How many σ bonds and π bonds are there in H3C–CH2–CH CH–CH2–C CH ? (A) 16, 3 (B) 13, 2 (C) 10, 2 (D) 10, 3 (E) 14, 3

29. ________________ is a method of separation that employs a system with two phases of matter, including a mobile phase and a stationary phase. (A) Chromatography (B) Distillation (C) Homogenization (D) Vaporization (E) Filtration

30. Which of the following is an example of nitrogen fixation? (A) Absorption of NH3 and its transformation into to N2. (B) Absorption of NH3 and its transformation into to NO2. (C) Absorption of N2 and its transformation into elemental nitrogen. (D) Absorption of N2 and its transformation into NH3. (E) Absorption of nitric acid and its transformation into N2.

62. Which of the statements below correctly describes the combustion of glucose, shown below? (A) Hydrogen in C6H12O6 is being reduced. (B) Oxygen in O2 is being oxidized. (C) Hydrogen in C6H12O6 is the reducing agent. (D) Oxygen in C6H12O6 is the oxidizing agent. (E) Carbon in C6H12O6 is being oxidized.

63. Reaction intermediates differ from activated complexes in that ________. (A) they are stable molecules with normal bonds and are frequently isolated (B) they are molecules with normal bonds rather than partial bonds and can occasionally be isolated (C) they are intermediate structures which have characteristics of both reactants and products (D) they are unstable and can never be isolated (E) all reactions involve reaction intermediates, but not all have activated complexes

64. Select the Lewis structure for XeO2F2 which correctly minimizes formal charges. (A) (B) (C) (D) (E)

65. Which species has the highest bond order? (A) NO+ (B) O2 (C) O2 − (D) O2 2− (E) NO−

66. What hybridization is present in the phosphorus atom in PCl3 and PCl5, respectively? (A) sp 2 , d 2 sp 3 (B) sp 2 , dsp3 (C) dsp, dsp3 (D) sp 3 , d 2 sp 3 (E) sp 3 , dsp3

67. The spectrochemical series is I– < Br– < Cl– < F– < OH– < H2O < NH3 < en < NO2– < CN– . Which of the following complexes will absorb visible radiation of the highest energy? (A) [Co(H2O)6] 3+ (B) [CoI6] 3– (C) [Co(OH)6] 3– (D) [Co(en)3] 3+ (E) [CoCl6] 3–