The enthalpy of precipitation of six common univalent cations with the tetraphenylborate anion has been measured at 25.0°C. Reaction entropies range from -8.24kcal/mole for ammonium to -19.7 kcal/mole for silver(I). The entropy of reaction was computed from the above measurements and the corresponding Gibbs free energy changes. A linear relationship exists between ΔF°′ and ΔH°′. The entropy of precipitation of ammonium ions was +5.0 e.u., an unusually large positive value. © 1971.
Carr, P. W. (1971). The enthalpy of precipitation of univalent cations with tetraphenylborate by titration calorimetry. Thermochimica Acta, 2(6), 505–511. https://doi.org/10.1016/0040-6031(71)80020-5