Answer:
ΔHf C₇H₁₄ = 137.6 kJ/mol
Step-by-step explanation:
The following equation represents the combustion of liquid cyclopentane:
C₇H₁₄ (l) + 10,5O₂ (g) → 7CO₂ (g) + 7H₂O (g)
The standard heat of combustion for this reaction is ΔHc = -4589.6 kJ/mol.
ΔHc can be calculated by the following equation:
ΔHc = ∑ΔHf products + ∑ΔHf reactants
ΔHc = (7ΔHf CO₂ + 7ΔHf H₂O) - (ΔHf C₇H₁₄ + 10.5ΔHf O₂)
Therefore, we can calculate the standard heat of formation of C₇H₁₄ :
ΔHf C₇H₁₄ = - ΔHc +7ΔHf CO₂+7ΔHf H₂O - 10.5ΔHf O₂
ΔHc = -4589.6 kJ/mol, ΔHf CO₂ = -394.0 kJ/mol, ΔHf H₂O = -242.0 kJ/mol, ΔHf O₂ = 0
ΔHf C₇H₁₄ = 4589.6 + 7x(-394.0) + 7x(-242.0) - 10.5x0
ΔHf C₇H₁₄ = 137.6 kJ/mol