Answer to Question #151298 in Physical Chemistry for STA MARIA, IAN PAUL D.

Question

1. The heat of combustion of 1 mole of C2H4 is given as: 

C2H4(g) + 3O2(g) →  2CO2(g) + 2H2O(g) ΔHrxn = ? kJ 

Answer 1

C₂H₄ + 3O₂ ---> 2CO₂ + 2 H₂O

From Appendix table

∆H^°_f C₂H₄ = 52.3Kj/mol

∆H^°_fCO₂= -393.5Kj/mol

∆H^°_f H₂O_(g) = -241.8Kj/mol

∆H°_rxn= ∆H°_products - ∆H°_reactants

∆H°_rxn = [2(-393.5)+2(-241.8)] - [52.3]

∆H°_rxn = -1322.9KJ/mol