Answer:
The heat of formation = Heat of formation of the products - Heat of formation of the reactants
= -2323 + 104 = -2219 ≈ -2218.6 kJ/mol.
Explanation:
The law of conservation of energy states that the total energy is constant in any process. Energy may change in form or be transferred from one system to another, but the total remains the same
The heat of formation of C₃H₈ is 3C + 4 H₂ → C₃H₈ [tex]\Delta H^{\circ}_f[/tex] -104 kJ/mol
The heat of formation of O₂ is O₂ (g) → O₂ (g) [tex]\Delta H^{\circ}_f[/tex] 0 kJ/mol
The heat of formation of H₂O is H₂(g) + 1/2 O₂→ H₂O (g) [tex]\Delta H^{\circ}_f[/tex] -286kJ/mol
The heat of formation of CO₂ is C (s) + O₂ (g) → CO₂ (g) [tex]\Delta H^{\circ}_f[/tex] -393 kJ/mol
Therefore, in the given reaction we have;
C₃H₈ + 4 O₂ → 3 CO₂ + 4 H₂O
The heat of formation = Heat of formation of the products - Heat of formation of the reactants
The heat of formation = 3 × (-393) + 4 × (-286) - (-104) = -2219 ≈ -2218.6 kJ/mol.
