Answer to Question #55533 in General Chemistry for Aleshia

Question

1. Given the data.
N2(g) + O2(g) 2 NO(g) ΔH = +180.7 kJ
2 NO(g) + O2(g) 2 NO2(g) ΔH = −113.1 kJ
2 N2O(g) 2 N2(g) + O2(g) ΔH = − 163.2 kJ
Use Hess’s Law to calculate ΔH for the reaction
N2O(g) + NO2(g) 3 NO(g)
Show your work.
2. Calcium carbide (CaC2) reacts with water to form acetylene (C2H2) and Ca(OH)2. From the
following enthalpy of reaction data and data in Appendix C in textbook, calculate ΔHf° for
CaC2(s):
CaC2(s) + 2 H2O(l) Ca(OH)2(s) + C2H2 (g) ΔH = −127.2kJ
3. Using average bond enthalpies, predict which of the following reactions will be most
exothermic:
a) C(g) + 2 F2(g) CF4(g)
b) CO(g) +3 F2(g) CF4(g) + OF2(g)
c) CO2(g) + 4 F2(g) CF4(g) + 2 OF2(g)