80. Given Cu₂O_(s) + 1/2O_2(g) → 2CuO_(s) , ΔH° = −144 kJ and Cu₂O_(s) → Cu_(s) + CuO_(s) , ΔH° = +11 kJ Calculate the standard enthalpy of formation of CuO(s) .
(A) −155 kJ
(B) +299 kJ
(C) +155 kJ
(D) −299 kJ
(E) −166 kJ

76. Consider the following reaction:. The equilibrium constant K is about 0.0196 at 115 °C. Calculate Kp at this temperature? (A) 0.196 (B) 0.624 (C) 0.285 (D) 22.9 (E) 2.9

77. The equilibrium constant for reaction (A) K 4 (B) 4K (C) 1/4 K (D) 1/K4 (E) - K 4 

78. The pH of a 0.005 M K2O aqueous solution should be ________. (A) 11.7 (B) 7.0 (C) 2.3 (D) 12.0 (E) 5.0

79. How long will it take to produce 18.2 g of Ag (atomic mass = 107.87 amu) from a solution of AgNO3 using a current of 10.00 amp? (F = 96500 C/mol) (A) 3.26✖103 s (B) 8.14✖102 s (C) 4.88✖103 s (D) 1.63✖103 s (E) 5.43✖103 s

81. Calculate E°cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous.   Overall reaction: MnO4–(aq) + 2H2O(l) + 3Co2+ (aq)MnO2(s) + 3Co3+(aq) + 4OH– (aq) (A) E°cell = –1.23 V, spontaneous (B) E°cell = –1.23 V, nonspontaneous (C) E°cell = 1.23 V, spontaneous (D) E°cell = 1.23 V, nonspontaneous (E) E°cell = –0.05 V, nonspontaneous

 82. The successive packing pattern for a hexagonal closest packed structures is which of the following? (A) ABCABC (B) ABCCBA (C) ABABAB (D) ABAABA (E) AABBAA

83. Identify the missing particle in the following equation:(A) (B) (C) (D)(E) None of the above.

84. How many valence electrons are there in an atom with the electron configuration [noble gas]ns 2 (n – 1)d 10 np 3 ? (A) 2 (B) 3 (C) 5 (D) 10 (E) 15

85. For the process CHCl3(s) → CHCl3(l) , ΔH° = 9.19 kJ/mol and the melting point of chloroform is –64 °C. Calculate ΔS° ? (A) 43.9 J/mol/K (B) 53.9 J/mol/K (C) 26.3 J/mol/K (D) 75.2 J/mol/K (E) None of the above.

86. Atomic orbitals developed using quantum mechanics ________. (A) describe regions of space in which one is most likely to find an electron (B) describe exact paths for electron motion (C) give a description of the atomic structure which is essentially the same as the Bohr model (D) allow scientists to calculate an exact volume for the hydrogen atom (E) are in conflict with the Heisenberg Uncertainty Principle