C2H5OH (ℓ ethanol) + 3 O2 (g) → 2 CO2 (g) + 3 H2O (g)

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Reaction Type:

Combustion

Stoichiometry

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C2H5OH         Mass: g
O2             Mass: g  or Gas Volume: L
CO2            Mass: g  or Gas Volume: L
H2O            Mass: g  or Gas Volume: L

Enthalpy of Reaction

[2ΔHf(CO2 (g)) + 3ΔHf(H2O (g))] - [1ΔHf(C2H5OH (ℓ ethanol)) + 3ΔHf(O2 (g))]
[2(-393.51) + 3(-241.82)] - [1(-276.98) + 3(0)] = -1235.5 kJ
-1,235.50 kJ     (exothermic)

Entropy Change

[2ΔSf(CO2 (g)) + 3ΔSf(H2O (g))] - [1ΔSf(C2H5OH (ℓ ethanol)) + 3ΔSf(O2 (g))]
[2(213.68) + 3(188.72)] - [1(161.04) + 3(205.03)] = 217.39 J/K
217.39 J/K     (increase in entropy)

Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[2ΔGf(CO2 (g)) + 3ΔGf(H2O (g))] - [1ΔGf(C2H5OH (ℓ ethanol)) + 3ΔGf(O2 (g))]
[2(-394.38) + 3(-228.59)] - [1(-174.18) + 3(0)] = -1300.35 kJ
-1,300.35 kJ     (spontaneous)

From ΔG = ΔH - TΔS:
-1300.31 kJ     (spontaneous)

Equilibrium Constant, K (at 298.15 K)

6.67021676309683E+227
This process is favorable at 25°C.

Reference(s):

Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; pp 97, 223.

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