Page 1302 - Chemistry--atom first

1292 Answer Key
29. 22.6. Since the mass and the heat capacity of the solution is approximately equal to that of the water, the two- fold increase in the amount of water leads to a two-fold decrease of the temperature change.
31. 11.7 kJ
33. 30%
35. 0.24 g
37.1.4 102 Calories
39. The enthalpy change of the indicated reaction is for exactly 1 mol HCL and 1 mol NaOH; the heat in the example is produced by 0.0500 mol HCl and 0.0500 mol NaOH.
41. 25 kJ mol−1
43. 81 kJ mol−1
45. 5204.4 kJ 47.1.83 10−2 mol 49. –802 kJ mol−1 51. 15.5 kJ/oC
53. 7.43 g 55.Yes.
57. 459.6 kJ
59. −495 kJ/mol 61. 44.01 kJ/mol 63. −394 kJ
65. 265 kJ
67. 90.3 kJ/mol
69. (a) −1615.0 kJ mol−1; (b) −484.3 kJ mol−1; (c) 164.2 kJ; (d) −232.1 kJ
71. −54.04 kJ mol−1
73. −2660 kJ mol−1
75. 67.1 kJ
77. −122.8 kJ
79. 3.7 kg
81. On the assumption that the best rocket fuel is the one that gives off the most heat, B2H6 is the prime candidate. 83. −88.2 kJ
85. (a) (b) 330 L; (c) −104.5 kJ mol−1; (d) 75.4 °C
88. (a) −114 kJ; (b) 30 kJ;
(c) −1055 kJ
91. The specific average bond distance is the distance with the lowest energy. At distances less than the bond distance, the positive charges on the two nuclei repel each other, and the overall energy increases.
92. The greater bond energy is in the figure on the left. It is the more stable form. 94.
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