Butane Combustion: Calculating Enthalpy of Combustion
Calculating Enthalpy of Combustion of Butane
Butane (C₄H₁₀) combusts in the presence of oxygen to form CO₂ (g) and H₂O(g) as shown in the reaction:
2 C₄H₁₀ + 13 O₂ → 8 CO₂ + 10 H₂O
Given the heat of formation of:
- C₄H₁₀ (butane) = -125.7 kJ/mol
- CO₂ = -393.5 kJ/mol
- H₂O = -241.82 kJ/mol
Using the formula for enthalpy of combustion:
ΔH = ∑Hproducts - ∑Hreactants
Calculating for the enthalpy of combustion:
ΔH = 8(-241.82) + 10(-393.5) - 2(-125.7)
ΔH = -5314.8 kJ/mol
This energy corresponds to the combustion of 2 moles of butane. Therefore, for 1 mole, the energy required for the combustion of butane is:
-2657.4 kJ/mol
What is the enthalpy of combustion, per mole, of butane?
The enthalpy of combustion, per mole, of butane is -2657.4 kJ/mol.