## H2 (g) + 1 I2 (g) → 2 HI (g)

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Synthesis

## Stoichiometry

Enter a mass or volume in one of the boxes below. Upon hitting submit, the stoichiometric equivalents will be calculated for the remaining reactants and products. All gases are assumed to be at STP.

 H2             Mass: g or Gas Volume: L I2             Mass: g or Gas Volume: L HI             Mass: g or Gas Volume: L Heat Released: kJ

## Enthalpy of Reaction

[2ΔHf(HI (g))] - [1ΔHf(H2 (g)) + 1ΔHf(I2 (g))]
[2(26.48)] - [1(0) + 1(62.44)] = -9.48 kJ
-9.48 kJ     (exothermic)

## Entropy Change

[2ΔSf(HI (g))] - [1ΔSf(H2 (g)) + 1ΔSf(I2 (g))]
[2(206.48)] - [1(130.59) + 1(260.58)] = 21.79 J/K
21.79 J/K     (increase in entropy)

## Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[2ΔGf(HI (g))] - [1ΔGf(H2 (g)) + 1ΔGf(I2 (g))]
[2(1.72)] - [1(0) + 1(19.36)] = -15.92 kJ
-15.92 kJ     (spontaneous)

From ΔG = ΔH - TΔS:
-15.98 kJ     (spontaneous)

## Equilibrium Constant, K (at 298.15 K)

615.48648952
This process is favorable at 25°C.