60. Rank the following molecules in order of decreasing C-C bond length of their shortest C-C bonds. ① benzene ② 1,3-butadiene (CH₂CHCHCH₂) ③ 1,2-propadiene (CH₂CCH₂) ④ethyne (HCCH)
(A) ① ＞ ②＞ ③ ＞④ 
(B) ④＞ ③＞ ②＞ ①
(C) ③＞ ②＞ ④ ＞ ① 
(D) ①＞ ③＞ ② ＞ ④ 
(E) ④＞ ② ＞ ③＞ ① 

56. Which pair of words correctly completes this statement: Ultraviolet light is more dangerous than infrared light because it has more energy. The _______________ of ultraviolet light is _____________ than infrared light. (A) wavelength – longer (B) frequency – higher (C) speed – greater (D) speed – less (E) frequency – lower

57. Which orbital diagram violates the rule "no two electrons can have the same set of four identical quantum numbers"?(A)(B)(C)(D)(E)

58. Which of the following plots correctly describe ideal gas behavior? (A)①②③ (B) only① and② (C) only① and③ (D) only② and③ (E) only①

59. These compounds are: (A) enantiomers (B) diasteroisomers (C) conformers (D) geometrical isomers (E) identical

II. Choose one correct answer for the following questions61. Which one is CORRECT for buffer capacity of a solution? (A) It is defined as the number of moles of a strong acid or a strong base that cause 1 mL of the buffer to undergo a 1.00-unit change in pH. (B) It depends only on the total concentration of buffers, not on their concentration ratio. (C) The pKa of the acid chosen for a given application should lie within ± 1 unit of the desired pH for the buffer. (D) A buffer solution of any desired pH can be prepared by combining calculated quantities of buffer pair, no need any adjustment. (E) Dissociation constants would not interfere with the predicted pH values.

62. There is a titration of 50.00 mL of 0.0500 M Fe2+ with 0.1000 M Ce4+ in a medium (1.0 M H2SO4). Calculate the potential after the addition of 25.00 mL of Ce4+. Ce4+ + e- → Ce3+      Eo = 1.44 V (1 M H2SO4) Fe3+ + e- → Fe2+       Eo = 0.68 V (1 M H2SO4) (A) 0.64 V (B) 1.06 V (C) 1.56 V (D) 2.01 V (E) 2.21 V

63. What mass of Ba(IO3)2 (487 g/mol) (Ksp = 1.57 × 10-9) can be dissolved in 400.0 mL of water at 25℃? (A) 0.732 mg (B) 5.45 mg (C) 0.142 g (D) 0.178 g (E) 0.280 g

64. The iron in a 0.6656-g ore sample was reduced quantitatively to the +2 state and then titrated with 26.75 mL of the KMnO4 solution (0.02966 M). Calculate the percentage of Fe2O3 (Fe=55.8 g/mol) in the sample. (A) 95.12 % (B) 47.56 % (C) 43.12 % (D) 38.04 % (E) 19.02 %

65. Which of the following compounds does NOT react with acetyl chloride? (A) C2H5OH (B) C6H6 + AlCl3 (C) CH3COONa (D) C2H5Cl (E) C2H5NHC2H4OH

66. A compound exhibits an infrared band at 2245 cm-1 and is hydrolysed by mineral acid to give an organic acid. The original compound is: (A) an ester (B) an amide (C) a nitrile (D) an acid anhydride (E) an alkyne