CaCrO4 (s) → Ca+2 (aq) + CrO4-2 (aq)

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Reaction Type:

Dissociation of an ionic compound in water

Enthalpy of Reaction

[1ΔHf(Ca+2 (aq)) + 1ΔHf(CrO4-2 (aq))] - [1ΔHf(CaCrO4 (s))]
[1(-542.83) + 1(-881.15)] - [1(-1379.05)] = -44.9300000000001 kJ
-44.93 kJ     (exothermic)

Entropy Change

[1ΔSf(Ca+2 (aq)) + 1ΔSf(CrO4-2 (aq))] - [1ΔSf(CaCrO4 (s))]
[1(-53.14) + 1(50.21)] - [1(133.89)] = -136.82 J/K
-136.82 J/K     (decrease in entropy)

Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[1ΔGf(Ca+2 (aq)) + 1ΔGf(CrO4-2 (aq))] - [1ΔGf(CaCrO4 (s))]
[1(-553.54) + 1(-727.85)] - [1(-1277.38)] = -4.00999999999976 kJ
-4.01 kJ     (spontaneous)

From ΔG = ΔH - TΔS:
-4.14 kJ     (spontaneous)

Equilibrium Constant, K (at 298.15 K)

5.0415107331
This process is close to or at equilibrium at 25°C.

Enter an initial concentration for the ionic compound. Upon hitting submit, Ksp (5.0415107331) will be used to calculate the equilibrium concentration for all species.

CaCrO4 Ca+2 CrO4-2
Initial M   0 0
Change -x +x +x
Equilibrium