## 2 KMnO4 (aq) + 3 KCN (aq) + H2O (ℓ) → 2 MnO2 (s) + 2 KOH (aq) + 3 KOCN (aq)

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## 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.

 KMnO4          Mass: g or Solution Volume: mL of Concentration: mol/L KCN            Mass: g or Solution Volume: mL of Concentration: mol/L H2O            Mass: g MnO2           Mass: g KOH            Mass: g KOCN           Mass: g Heat Released: kJ

## Enthalpy of Reaction

[2ΔHf(MnO2 (s)) + 2ΔHf(KOH (aq)) + 3ΔHf(KOCN (aq))] - [2ΔHf(KMnO4 (aq)) + 3ΔHf(KCN (aq)) + 1ΔHf(H2O (ℓ))]
[2(-520.03) + 2(-482.39) + 3(-398.42)] - [2(-793.81) + 3(-191.73) + 1(-285.83)] = -751.46 kJ
-751.46 kJ     (exothermic)

## Entropy Change

[2ΔSf(MnO2 (s)) + 2ΔSf(KOH (aq)) + 3ΔSf(KOCN (aq))] - [2ΔSf(KMnO4 (aq)) + 3ΔSf(KCN (aq)) + 1ΔSf(H2O (ℓ))]
[2(53.05) + 2(91.75) + 3(209.19)] - [2(293.71) + 3(298.31) + 1(69.91)] = -635.09 J/K
-635.09 J/K     (decrease in entropy)

## Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[2ΔGf(MnO2 (s)) + 2ΔGf(KOH (aq)) + 3ΔGf(KOCN (aq))] - [2ΔGf(KMnO4 (aq)) + 3ΔGf(KCN (aq)) + 1ΔGf(H2O (ℓ))]
[2(-465.18) + 2(-440.58) + 3(-380.79)] - [2(-730.57) + 3(-244.56) + 1(-237.18)] = -521.890000000001 kJ
-521.89 kJ     (spontaneous)

From ΔG = ΔH - TΔS:
-562.11 kJ     (spontaneous)

## Equilibrium Constant, K (at 298.15 K)

2.7306106143e+091
This process is favorable at 25°C.