Calculate DH for the reaction: C2H4 (g) + H2 (g) -> C2H6 (g), from the following data.
C2H4 (g) + 3 O2 (g) -> 2 CO2 (g) + 2 H2O (l) (-1411)
C2H6 (g) + 3½ O2 (g) -> 2 CO2 (g) + 3 H2O (l) (-1560 kJ)
H2 (g) + ½ O2 (g) -> H2O (l) (-285.8 kJ)
How do I construct thew Hess Cycle for this equation