Table 4.

Extrapolated drop solution enthalpies of bulk (zero surface area) materials, their enthalpies of formation from oxides and elements, their estimated standard entropies and estimated entropies of formation, and Gibbs free energies of formation from elements at 298 K

Phases	Average composition of the Phase	ΔHds,corr,bulk,* kJ/mol	ΔH°f-ox*, ΔH(with redox),† kJ/mol	ΔH°f-ox, ΔH(without redox),‡ (kJ/mol)	∆H°f(bulk),§ (kJ/mol)	So298 (standard entropy),¶ J/mol⋅K	ΔG°f(bulk),# kJ/mol
CR2	K0.11·MnO1.94	113.75 ± 3.00	−43.70 ± 3.16	−15.18 ± 3.42	−529.24 ± 0.94	58.32 ± 0.21	−540.31 ± 0.63
NaBi	Na0.09·MnO1.82	155.64 ± 3.47	−82.47 ± 3.67	−61.99 ± 4.49	−522.92 ± 0.71	64.13 ± 0.12	−556.00 ± 0.77
KBi	K0.21·MnO1.87	122.65 ± 3.58	−71.34 ± 3.78	−52.32 ± 3.42	−536.86 ± 1.14	58.28 ± 0.17	−580.64 ± 0.68
CaBi	Ca0.12·MnO1.81	129.80 ± 3.10	−58.22 ± 3.21	−33.86 ± 2.30	−563.26 ± 0.76	58.36 ± 0.11	−546.65 ± 0.80

Cryptomelane: CR2, NaBi, KBi, and CaBi (Bi, birnessite). *Extrapolated drop solution enthalpy for bulk scale samples (no surface hydration and x = 0 surface area). Estimated standard enthalpy of formation for bulk phases were computed from both oxides, including ^†redox enthalpy (ΔH°_f-ox*) and ^‡without redox energetics (ΔH°_f-ox), as well as from the ^§elements [∆H°_f(bulk)]. Estimated ^¶S^o₂₉₈ (standard entropy) for bulk phases. ^#Estimated bulk-scale reaction Gibbs free energy of formation was computed as G°_f(bulk) = ΔH°_f(bulk) – TΔS°₂₉₈ using the estimated standard entropies (S°₂₉₈).