## MgCO3 (s) → Mg+2 (aq) + CO3-2 (aq)

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## Reaction Type:

Dissociation of an ionic compound in water

## Enthalpy of Reaction

[1ΔHf(Mg+2 (aq)) + 1ΔHf(CO3-2 (aq))] - [1ΔHf(MgCO3 (s))]
[1(-466.85) + 1(-677.14)] - [1(-1095.79)] = -48.2 kJ
-48.20 kJ     (exothermic)

## Entropy Change

[1ΔSf(Mg+2 (aq)) + 1ΔSf(CO3-2 (aq))] - [1ΔSf(MgCO3 (s))]
[1(-138.07) + 1(-56.9)] - [1(65.69)] = -260.66 J/K
-260.66 J/K     (decrease in entropy)

## Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[1ΔGf(Mg+2 (aq)) + 1ΔGf(CO3-2 (aq))] - [1ΔGf(MgCO3 (s))]
[1(-454.8) + 1(-527.9)] - [1(-1012.11)] = 29.41 kJ
29.41 kJ     (nonspontaneous)

From ΔG = ΔH - TΔS:
29.52 kJ     (nonspontaneous)

## Equilibrium Constant, K (at 298.15 K)

7.0356499134e-006
This process is not favorable at 25°C.

Enter an initial concentration for the ionic compound. Upon hitting submit, Ksp (7.0356499134e-006) will be used to calculate the equilibrium concentration for all species.

 MgCO3 Mg+2 CO3-2 Initial M 0 0 Change -x +x +x Equilibrium