19. Chemical Thermodynamics
Entropy Calculations
15PRACTICE PROBLEM
Methane gas, the main component in biogas, is one of the clean fuels used for transportation. It is a useful fuel source when it undergoes combustion:
CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l)
Using the data below, calculate ∆H° and ∆S° for the reaction. Assume that these values do not change significantly with temperature.
ΔH° (kJ/mol) S° (J/mol•K)
CH4(g) –74.8 186.3
O2(g) 0 205.0
CO2(g) –393.5 213.6
H2O(l) –285.83 69.91
Methane gas, the main component in biogas, is one of the clean fuels used for transportation. It is a useful fuel source when it undergoes combustion:
CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(l)
Using the data below, calculate ∆H° and ∆S° for the reaction. Assume that these values do not change significantly with temperature.
ΔH° (kJ/mol) S° (J/mol•K)
CH4(g) –74.8 186.3
O2(g) 0 205.0
CO2(g) –393.5 213.6
H2O(l) –285.83 69.91