THERMOCHEMISTRY QUIZ Part IV

1. The standard enthalpy of formation of propane, C3H8, is -103.6 kJ/mole. Calculate the heat of combustion of one mole of C3H8. The heats of formation of CO2(g) and H2O(l) are -394 kJ/mole and -285.8 kJ/mole respectively.
a. 2220
b. 2060.0
c. 1856
d. 1721.2
e. -1939.1
2. The standard enthalpy of formation of methanol, CH3OH, is -238.6 kJ mole. Calculate the heat of combustion of one mole of CH3OH. The heats of formation of CO2(g) and H2O(l) are -394 kJ/mole and -285.8 kJ/mole respectively.
a. 1300
b. 1142
c. 976
d. 854
e. 727
3. The heat of formation of CO2(g) is -394 kJ/mole and that of H2O(l) is -286 kJ/mole. The heat of combustion of C5H12 is -3534 kJ/mole. What is the heat of formation of C5H12?
C5H12(l) + 8 O2(g) --> 5 CO2(g) + 6 H2O(l)
a. -7220
b. -152
c. -108
d. +108
e. +152
4. Using the following information calculate the heat of formation of N2H4.
N2H4(l) + O2(g) --> N2(g) + 2 H2O(l)Ho = -622.4 kJ
Hof H2O(l) = -285.9 kJ/mole
a. +98.6
b. +90.4
c. +70.6
d. +50.6
e. +33.5
5. Using the following information calculate the heat of formation of Fe2O3.
Fe2O3(s) + 3 H2(g) --> 2 Fe(s) + 3 H2O(l) Ho = -35.5 kJ
Hof H2O(l) = -285.9 kJ/mole
a. -893.2
b. -822.2
c. -464.4
d. -393.4
e. -250.4
6. Using the following information calculate the heat of formation of CCl4.
CH4(g) + 4 Cl2(g) --> CCl4(g) + 4 HCl(g) Ho = -402 kJ
Hof CH4(g) = -74.85 kJ/mole; Hof HCl(g) = -92.30 kJ/mole
a. -132
b. -108
c. -54.0
d. +54.0
e. +132
7. The heat of formation of PCl3(g) is -287.0 kJ/mole. What is the heat of reaction for the following process?
2 PCl3(g) --> 2 P(s) + 3 Cl2(g)
a. -612.8
b. -306.4
c. +153.2
d. +306.4
e. + 612.8
8. Given the heat of reaction, Ho = -2029.7 kJ, and the indicated heats of formation, determine the heat of formation of NH4NO3(s) in kJ.
2 Al(s) + 3 NH4NO3(s) --> 3 N2(g) + 6 H2O(g) + Al2O3(s)
Hof H2O(g) = -241.8 kJ; Hof Al2O3(s) = -1675.7 kJ
a. +365.6
b. +298.2
c. -298.2
d. -365.6
e. -442.5
9. The heats of formation of CO2(g) and H2O(l) are -394 kJ/mole and -285.8 kJ/mole respectively. Using the data for the following combustion reaction, calculate the heat of formation of C3H8(g).
C3H8(g) + 5 O2(g) --> 3 CO2(g) + 4 H2O(l) Ho = -2221.6 kJ
a. -143.3
b. -103.6
c. 20.4
d. 185.4
e. 212.2
10. The heats of formation of CO2(g) and H2O(l) are -394 kJ/mole and -285.8 kJ/mole respectively. Using the data for the following combustion reaction, calculate the heat of formation of C3H4(g).
C3H4(g) + 4 O2(g) --> 3 CO2(g) + 2 H2O(l) Ho = -1939.1 kJ
a. -143.3
b. -103.8
c. 20.4
d. 185.4
e. 212.2