## 2 H3PO4 (aq) + 3 Na2SO3 (s) → 2 Na3PO4 (aq) + 3 H2O (ℓ) + 3 SO2 (g)

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## Reaction Type:

Double Displacement/Decomposition of a Sulfite

## 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.

 Heat Added: kJ H3PO4          Mass: g or Solution Volume: mL of Concentration: mol/L Na2SO3         Mass: g Na3PO4         Mass: g H2O            Mass: g SO2            Mass: g or Gas Volume: L

## Enthalpy of Reaction

[2ΔHf(Na3PO4 (aq)) + 3ΔHf(H2O (ℓ)) + 3ΔHf(SO2 (g))] - [2ΔHf(H3PO4 (aq)) + 3ΔHf(Na2SO3 (s))]
[2(-1997.68) + 3(-285.83) + 3(-296.83)] - [2(-1277.38) + 3(-1090.35)] = 82.4699999999993 kJ
82.47 kJ     (endothermic)

## Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[2ΔGf(Na3PO4 (aq)) + 3ΔGf(H2O (ℓ)) + 3ΔGf(SO2 (g))] - [2ΔGf(H3PO4 (aq)) + 3ΔGf(Na2SO3 (s))]
[2(-1804.5) + 3(-237.18) + 3(-300.19)] - [2(-1018.8) + 3(-1002.07)] = -177.3 kJ
-177.30 kJ     (spontaneous)

From ΔG = ΔH - TΔS:
-176.92 kJ     (spontaneous)

## Equilibrium Constant, K (at 298.15 K)

1.157029665e+031
This process is favorable at 25°C.