## N2 (g) + 1 O2 (g) → 2 NO (g)

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Synthesis

## Stoichiometry

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 Heat Added: kJ N2             Mass: g or Gas Volume: L O2             Mass: g or Gas Volume: L NO             Mass: g or Gas Volume: L

## Enthalpy of Reaction

[2ΔHf(NO (g))] - [1ΔHf(N2 (g)) + 1ΔHf(O2 (g))]
[2(90.25)] - [1(0) + 1(0)] = 180.5 kJ
180.50 kJ     (endothermic)

## Entropy Change

[2ΔSf(NO (g))] - [1ΔSf(N2 (g)) + 1ΔSf(O2 (g))]
[2(210.65)] - [1(191.5) + 1(205.03)] = 24.77 J/K
24.77 J/K     (increase in entropy)

## Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[2ΔGf(NO (g))] - [1ΔGf(N2 (g)) + 1ΔGf(O2 (g))]
[2(86.57)] - [1(0) + 1(0)] = 173.14 kJ
173.14 kJ     (nonspontaneous)

From ΔG = ΔH - TΔS:
173.11 kJ     (nonspontaneous)

## Equilibrium Constant, K (at 298.15 K)

4.6290996243e-031
This process is not favorable at 25°C.

## Reference(s):

Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; pp 223-4, 302.