Reaction Type:
Dissociation of an ionic compound in water
Enthalpy of Reaction
[3ΔHf(Ca+2 (aq)) + 2ΔHf(PO4-3 (aq))] - [1ΔHf(Ca3(PO4)2 (s beta))]
[3(-542.83) + 2(-1277.38)] - [1(-4120.82)] = -62.4300000000003 kJ
-62.43 kJ (exothermic)
Entropy Change
[3ΔSf(Ca+2 (aq)) + 2ΔSf(PO4-3 (aq))] - [1ΔSf(Ca3(PO4)2 (s beta))]
[3(-53.14) + 2(-221.75)] - [1(235.98)] = -838.9 J/K
-838.90 J/K (decrease in entropy)
Free Energy of Reaction (at 298.15 K)
From ΔGf° values:
[3ΔGf(Ca+2 (aq)) + 2ΔGf(PO4-3 (aq))] - [1ΔGf(Ca3(PO4)2 (s beta))]
[3(-553.54) + 2(-1018.8)] - [1(-3884.84)] = 186.62 kJ
186.62 kJ (nonspontaneous)
From ΔG = ΔH - TΔS:
187.69 kJ (nonspontaneous)
Equilibrium Constant, K (at 298.15 K)
2.01266407461241E-33
This process is not favorable at 25°C.
Enter an initial concentration for the ionic compound. Upon hitting submit, Ksp (2.01266407461241E-33) will be used to calculate the equilibrium concentration for all species.