## 4 KO2 (s) + 2 H2O (ℓ) → 4 KOH (s) + 3 O2 (g)

Back to reactions list

## 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 KO2            Mass: g H2O            Mass: g KOH            Mass: g O2             Mass: g or Gas Volume: L

## Enthalpy of Reaction

[4ΔHf(KOH (s)) + 3ΔHf(O2 (g))] - [4ΔHf(KO2 (s)) + 2ΔHf(H2O (ℓ))]
[4(-425.85) + 3(0)] - [4(-284.51) + 2(-285.83)] = 6.29999999999973 kJ
6.30 kJ     (endothermic)

## Entropy Change

[4ΔSf(KOH (s)) + 3ΔSf(O2 (g))] - [4ΔSf(KO2 (s)) + 2ΔSf(H2O (ℓ))]
[4(78.87) + 3(205.03)] - [4(122.59) + 2(69.91)] = 300.39 J/K
300.39 J/K     (increase in entropy)

## Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[4ΔGf(KOH (s)) + 3ΔGf(O2 (g))] - [4ΔGf(KO2 (s)) + 2ΔGf(H2O (ℓ))]
[4(-379.07) + 3(0)] - [4(-240.58) + 2(-237.18)] = -79.5999999999999 kJ
-79.60 kJ     (spontaneous)

From ΔG = ΔH - TΔS:
-83.26 kJ     (spontaneous)

## Equilibrium Constant, K (at 298.15 K)

8.8326825311e+013
This process is favorable at 25°C.

## Reference(s):

Ebbing, Darrell D. General Chemistry 3rd ed.; Houghton Mifflin Company: Boston, MA, 1990; pp 135, 227.