Using Hess's Law and Equations 1-3 Below, Find ΔH° at 25°C

question 80

Multiple Choice

Using Hess's law and equations 1-3 below, find ΔH° at 25°C for the oxidation of C₂H₅OH(l) .C₂H₅OH(l) + 3O₂(g) → 3H₂O(l) + 2CO₂(g)
1) C₂H₄(g) + 3O₂(g) → 2CO₂(g) + 2H₂O(l)
ΔH° = -1411 kJ
2) C(graphite) + 3H₂(g) + (1/2) O₂(g) → C₂H₅OH(l)
ΔH° = -278 kJ
3) C₂H₄(g) + H₂O(l) → C₂H₅OH(l)
ΔH° = -44 kJ

• A) -1367 kJ
• B) 44 kJ
• C) 632 kJ
• D) -1742 kJ
• E) none of these

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