## 4 NH3 (g) + 3 O2 (g) → 2 N2 (g) + 6 H2O (g)

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## Stoichiometry

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 NH3            Mass: g or Gas Volume: L O2             Mass: g or Gas Volume: L N2             Mass: g or Gas Volume: L H2O            Mass: g or Gas Volume: L Heat Released: kJ

## Enthalpy of Reaction

[2ΔHf(N2 (g)) + 6ΔHf(H2O (g))] - [4ΔHf(NH3 (g)) + 3ΔHf(O2 (g))]
[2(0) + 6(-241.82)] - [4(-46.11) + 3(0)] = -1266.48 kJ
-1,266.48 kJ     (exothermic)

## Entropy Change

[2ΔSf(N2 (g)) + 6ΔSf(H2O (g))] - [4ΔSf(NH3 (g)) + 3ΔSf(O2 (g))]
[2(191.5) + 6(188.72)] - [4(192.34) + 3(205.03)] = 130.87 J/K
130.87 J/K     (increase in entropy)

## Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[2ΔGf(N2 (g)) + 6ΔGf(H2O (g))] - [4ΔGf(NH3 (g)) + 3ΔGf(O2 (g))]
[2(0) + 6(-228.59)] - [4(-16.48) + 3(0)] = -1305.62 kJ
-1,305.62 kJ     (spontaneous)

From ΔG = ΔH - TΔS:
-1305.50 kJ     (spontaneous)

## Equilibrium Constant, K (at 298.15 K)

5.5905608135e+228
This process is favorable at 25°C.

## Reference(s):

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