What is the standard heat of formation (∆Hºf) of gaseous ethylene, C₂H₄(g)?
H₂(g) + ½ O₂(g)  H₂O(g) ∆Hº = –242 kJ mol–1
2 C(s, graphite) + 3 H₂(g) + ½ O₂(g)  C₂H₅OH(l) ∆Hº = –278 kJ mol–1
C₂H₄(g) + H₂O(g)  C₂H₅OH(l) ∆Hº = –88 kJ mol–1

Question

What is the standard heat of formation (∆Hºf) of gaseous  ethylene, C2H4(g)?
H2(g) + ½ O2(g)  H2O(g) ∆Hº = –242 kJ mol–1
2 C(s,  graphite) + 3 H2(g) + ½ O2(g)  C2H5OH(l) ∆Hº = –278 kJ mol–1
C2H4(g) + H2O(g)   C2H5OH(l) ∆Hº = –88 kJ mol–1

Accepted Answer

Correct answer: B.

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