Table 2 Thermodynamic quantities for the binding of calcium to the three phosphate ions from experiment (expt) and simulation (sim)

From: Redefined ion association constants have consequences for calcium phosphate nucleation and biomineralization

 

ΔG0 (kJ/mol)

ΔH0 (kJ/mol)

ΔS0 (J/K/mol)

\({K}_{1}\) (expt)

−3.7 ± 0.9

0.0 ± 77

12.5 ± 260

\({K}_{2}\) (expt)

−15.2 ± 0.3

1.3 ± 13

55.6 ± 43

\({K}_{2}\) (sim)

−14.0 ± 0.5

28 ± 5

140 ± 15

\({K}_{3}\) (expt)

−26.8 ± 0.5

20.8 ± 22

160 ± 74

\({K}_{3}\) (sim)

−22.8 ± 0.3

15 ± 3

128 ± 10

  1. The overall reaction is thermodynamically favourable even though the standard enthalpy change is not. The standard enthalpy calculated for the first ion association (\({K}_{1}\)) is zero – this follows from using the same ion association constant at both temperatures (Supplementary Section 4).
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