Respuesta :
The value of Δ H butane (g) = -124.7 kJ/mol
The value of Δ H CO2 (g) = -393.5 kJ/mol
The value of Δ H H2O (g) = -241.8 kJ/mol
Mass of butane, m = 8.30 gm
Molar mass of butane is 58 gm/mol
Consider the reaction,
C₄H₁₀ + 6.5 O₂ = 4CO₂ + 5H₂O
Calculating the value of Δ H° rxn:
ΔH°rxn = ∑nH° f (products) - ∑nH° f (reactants)
Substituting the values we get,
Δ H° rxn = 4 (-393.5) + 5 (-241.8) - (-124.7)
= -1574 -1209 + 124.7
= -2783 - 124.7
= -2658.3 kJ/mol
Now, calculate the number of moles of butane in 8.30 gm.
Number of moles = mass/molar mass
= 8.30 / 58
= 0.143 moles
Thus, the total energy released in the reaction is,
Q = number of moles × ΔH° rxn
= 0.143 × (2658.3)
= 380.14 kJ
Hence, the total heat released in the reaction is 380.14 kJ.
