## C2H4 (g ethylene) + 3 O2 (g) → 2 CO2 (g) + 2 H2O (ℓ)

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Combustion

## Stoichiometry

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 C2H4           Mass: g O2             Mass: g or Gas Volume: L CO2            Mass: g or Gas Volume: L H2O            Mass: g Heat Released: kJ

## Enthalpy of Reaction

[2ΔHf(CO2 (g)) + 2ΔHf(H2O (ℓ))] - [1ΔHf(C2H4 (g ethylene)) + 3ΔHf(O2 (g))]
[2(-393.51) + 2(-285.83)] - [1(52.3) + 3(0)] = -1410.98 kJ
-1,410.98 kJ     (exothermic)

## Entropy Change

[2ΔSf(CO2 (g)) + 2ΔSf(H2O (ℓ))] - [1ΔSf(C2H4 (g ethylene)) + 3ΔSf(O2 (g))]
[2(213.68) + 2(69.91)] - [1(219.2) + 3(205.03)] = -267.11 J/K
-267.11 J/K     (decrease in entropy)

## Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[2ΔGf(CO2 (g)) + 2ΔGf(H2O (ℓ))] - [1ΔGf(C2H4 (g ethylene)) + 3ΔGf(O2 (g))]
[2(-394.38) + 2(-237.18)] - [1(68.24) + 3(0)] = -1331.36 kJ
-1,331.36 kJ     (spontaneous)

From ΔG = ΔH - TΔS:
-1331.34 kJ     (spontaneous)

## Equilibrium Constant, K (at 298.15 K)

1.8078366893e+233
This process is favorable at 25°C.

## Reference(s):

Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; p 224.