Hydrolysis constant

Article
Talk

(Redirected from Base hydrolysis constant)

The word hydrolysis is applied to chemical reactions in which a substance reacts with water. In organic chemistry, the products of the reaction are usually molecular, being formed by combination with H and OH groups (e.g., hydrolysis of an ester to an alcohol and a carboxylic acid). In inorganic chemistry, the word most often applies to cations forming soluble hydroxide or oxide complexes with, in some cases, the formation of hydroxide and oxide precipitates.

Metal hydrolysis and associated equilibrium constant values

The hydrolysis reaction for a hydrated metal ion in aqueous solution can be written as:

p M^z+ + q H₂O ⇌ M_p(OH)_q^(pz–q) + q H⁺

and the corresponding formation constant as:

\beta _{pq}={\frac {[M_{p}(OH)_{q}^{(pz-q)}][H^{+}]^{q}}{[M^{z+}]^{p}}}

and associated equilibria can be written as:

MO_x(OH)_z–2x(s) + z H⁺ ⇌ M^z+ + (z–x) H₂O

MO_x(OH)_z–2x(s) + x H₂O ⇌ M^z+ + z OH⁻

p MO_x(OH)_z–2x(s) + (pz–q) H⁺ ⇌ M_p(OH)_q^(pz–q) + (pz–px–q) H₂O

Aluminium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[1]	Brown and Ekberg, 2016^[2]	Hummel and Thoenen, 2023^[3]
Al³⁺ + H₂O ⇌ AlOH²⁺ + H⁺	–4.97	−4.98 ± 0.02	−4.98 ± 0.02
Al³⁺ + 2 H₂O ⇌ Al(OH)₂⁺ + 2 H⁺	–9.3	−10.63 ± 0.09	−10.63 ± 0.09
Al³⁺ + 3 H₂O ⇌ Al(OH)₃ + 3 H⁺	–15.0	−15.66 ± 0.23	−15.99 ± 0.23
Al³⁺ + 4 H₂O ⇌ Al(OH)₄^– + 4 H⁺	–23.0	−22.91 ± 0.10	−22.91 ± 0.10
2 Al³⁺ + 2 H₂O ⇌ Al₂(OH)₂⁴⁺ + 2 H⁺	–7.7	−7.62 ± 0.11	−7.62 ± 0.11
3 Al³⁺ + 4 H₂O ⇌ Al₃(OH)₄⁵⁺ + 4 H⁺	–13.94	−14.06 ± 0.22	−13.90 ± 0.12
13 Al³⁺ + 28 H₂O ⇌ Al₁₃O₄(OH)₂₄⁷⁺ + 32 H⁺	–98.73	−100.03 ± 0.09	−100.03 ± 0.09
α-Al(OH)₃(s) + 3 H⁺ ⇌ Al³⁺ + 3 H₂O	8.5	7.75 ± 0.08	7.75 ± 0.08
γ-AlOOH(s) + 3 H⁺ ⇌ Al³⁺ + 2 H₂O		7.69 ± 0.15	9.4 ± 0.4

Americium(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	NIST46^[4]	Brown and Ekberg, 2016^[5]	Grenthe et al, 2020^[6]
Am³⁺ + H₂O ⇌ Am(OH)²⁺ + H⁺	–6.5 ± 0.1	–7.22 ± 0.03	–7.2 ± 0.5
Am³⁺ + 2 H₂O ⇌ Am(OH)₂⁺ + 2 H⁺	–14.1 ± 0.3	–14.9 ± 0.2	–15.1 ± 0.7
Am³⁺ + 3 H₂O ⇌ Am(OH)₃ + 3 H⁺	–25.7	–26.0 ± 0.2	–26.2 ± 0.5
Am³⁺ + 3 H₂O ⇌ Am(OH)₃(am) + 3 H⁺	–16.9 ± 0.1	–16.9 ± 0.8	–16.9 ± 0.8
Am³⁺ + 3 H₂O ⇌ Am(OH)₃(cr) + 3 H⁺	–15.2	–15.62 ± 0.04	–15.6 ± 0.6

Americium(V)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Brown and Ekberg, 2016^[7]	Grenthe et al, 2020^[6]
AmO₂⁺ + H₂O ⇌ AmO₂(OH) + H⁺	–10.7 ± 0.2
AmO₂⁺ + 2 H₂O ⇌ AmO₂(OH)₂^– + 2 H⁺	–22.9 ± 0.7
AmO₂⁺ + H₂O ⇌ AmO₂(OH)(am) + H⁺	–5.4 ± 0.4	–5.3 ± 0.5

Antimony(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[8]	Lothenbach et al., 1999;^[9] Kitamura et al., 2010^[10]	Filella and May, 2003^[11]
Sb(OH)₃ + H⁺ ⇌ Sb(OH)₂⁺ + H₂O	1.41	1.30	1.371
Sb(OH)₃ + H₂O ⇌ Sb(OH)₄^‒ + H⁺	‒11.82	‒11.93	‒11.70
0.5 Sb₂O₃(s) + 1.5 H₂O ⇌ Sb(OH)₃	‒4.24
Sb₂O₃(rhombic,s) + 3 H₂O ⇌ 2 Sb(OH)₃		‒8.72	‒10.00
Sb₂O₃(cubic,s) + 3 H₂O ⇌ 2 Sb(OH)₃			‒11.40

Antimony(V)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[8]	Lothenbach et al., 1999;^[9] Kitamura et al., 2010^[10]
Sb(OH)₅ + H₂O ⇌ Sb(OH)₆^‒ + H⁺	‒2.72	‒2.72
12 Sb(OH)₅ + 4 H₂O ⇌ Sb₁₂(OH)₆₄^4‒ + 4 H⁺	20.34	20.34
12 Sb(OH)₅ + 5 H₂O ⇌ Sb₁₂(OH)₆₅^5‒ + 5 H⁺	16.72	16.72
12 Sb(OH)₅ + 6 H₂O ⇌ Sb₁₂(OH)₆₆^6‒ + 6 H⁺	11.89	11.89
12 Sb(OH)₅ + 7 H₂O ⇌ Sb₁₂(OH)₆₇^7‒ + 7 H⁺	6.07	6.07
0.5 Sb₂O₅(s) + 2.5 H₂O ⇌ Sb(OH)₅	‒3.7
Sb₂O₅(am) + 5 H₂O ⇌ 2 Sb(OH)₅		‒7.400

Arsenic(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[12]	Nordstrom and Archer, 2003^[13]	Nordstrom et al., 2014^[14]
As(OH)₄^‒ + H⁺ ⇌ As(OH)₃ + H₂O	9.29	9.17	9.24 ± 0.02

Arsenic(V)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer^[12]	Khodakovsky et al. (1968)^[15]	Nordstrom and Archer, 2003^[13]	Nordstrom et al., 2014^[14]
H₂AsO₄^‒ + H⁺ ⇌ H₃AsO₄	2.24	2.21	2.26 ± 0.078	2.25 ± 0.04
HAsO₄^2‒ + H⁺ ⇌ H₂AsO₄^‒		6.93	6.99 ± 0.1	6.98 ± 0.11
AsO₄^3‒ + H⁺ ⇌ HAsO₄^2‒		11.51	11.80 ± 0.1	11.58 ± 0.05
HAsO₄^2‒ + 2 H⁺ ⇌H₃AsO₄	9.20
AsO₄^3‒ + 3 H⁺ ⇌ H₃AsO₄	20.70

Barium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[16]	Nordstrom et al., 1990^[17]	Brown and Ekberg, 2016^[18]
Ba²⁺ + H₂O ⇌ BaOH⁺ + H⁺	–13.47	–13.47	–13.32 ± 0.07

Berkelium(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Brown and Ekberg, 2016^[19]
Bk³⁺ + 3 H₂O ⇌ Bk(OH)₃(s) + 3 H⁺	–13.5 ± 1.0

Beryllium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[20]
Be²⁺ + H₂O ⇌ BeOH⁺ + H⁺	–5.10
Be²⁺ + 2 H₂O ⇌ Be(OH)₂ + 2 H⁺	–23.65
Be²⁺ + 3 H₂O ⇌ Be(OH)₃^– + 3 H⁺	–23.25
Be²⁺ + 4 H₂O ⇌ Be(OH)₄^2– + 4 H⁺	–37.42
2 Be²⁺ + H₂O ⇌ Be₂OH³⁺ + H⁺	–3.97
3 Be²⁺ + 3 H₂O ⇌ Be₃(OH)₃³⁺ + 3 H⁺	–8.92
6 Be²⁺ + 8 H₂O ⇌ Be₆(OH)₈⁴⁺ + 8 H⁺	–27.2
α-Be(OH)₂(cr) + 2 H⁺ ⇌ Be²⁺ + 2 H₂O	6.69

Bismuth

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[21]	Lothenbach et al., 1999^[9]	NIST46^[4]	Kitamura et al., 2010^[10]	Brown and Ekberg, 2016^[22]
Bi³⁺ + H₂O ⇌ BiOH²⁺ + H⁺	–1.0	–0.92	–1.1	–0.920	–0.92 ± 0.15
Bi³⁺ + 2 H₂O ⇌ Bi(OH)₂⁺ + 2 H⁺	(–4)	–2.56	–4.5	–2.560 ± 1.000	–2.59 ± 0.26
Bi³⁺ + 3 H₂O ⇌ Bi(OH)₃ + 3 H⁺	–8.86	–5.31	–9.0	–8.940 ± 0.500	–8.78 ± 0.20
Bi³⁺ + 4 H₂O ⇌ Bi(OH)₄^– + 4 H⁺	–21.8	–18.71	–21.2	–21.660 ± 0.870	–22.06 ± 0.14
3 Bi³⁺ + 4 H₂O ⇌ Bi3(OH)₄⁵⁺ + 4 H⁺		–0.80		–0.800
6 Bi³⁺ + 12 H₂O ⇌ Bi₆(OH)₁₂⁶⁺ + 12 H⁺		1.34		1.340	0.98 ± 0.13
9 Bi³⁺ + 20 H₂O = Bi₉(OH)₂₀⁷⁺ + 20 H⁺		–1.36		–1.360
9 Bi³⁺ + 21 H₂O = Bi₉(OH)₂₁⁶⁺ + 21 H⁺		–3.25		–3.250
9 Bi³⁺ + 22 H₂O = Bi9(OH)₂₂⁵⁺ + 22 H⁺		–4.86		–4.860
Bi(OH)₃(am) + 3 H⁺ = Bi³⁺ + 3 H₂O				31.501 ± 0.927
α-Bi₂O₃(cr) + 6 H⁺ = 2 Bi³⁺ + 3 H₂O		0.76
BiO_1.5(s, α) + 3 H⁺ = Bi³⁺ + 1.5 H₂O	3.46			31.501 ± 0.927	2.88 ± 0.64

Boron

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[23]	NIST46^[4]
B(OH)₃ + H₂O ⇌ Be(OH)₄⁺ + H⁺	–9.236	–9.236 ± 0.002
2 B(OH)₃ ⇌ B₂(OH)₅^– + H⁺	–9.36	–9.306
3 B(OH)₃ ⇌ B₃O₃(OH)₄^– + H⁺ + 2 H₂O	–7.03	–7.306
4 B(OH)₃ ⇌ B₄O₅(OH)₄^2– + 2 H⁺ + 3 H₂O	–16.3	–15.032

Cadmium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[24]	Powell et al., 2011^[25]	Brown and Ekberg, 2016^[26]
Cd²⁺ + H₂O ⇌ CdOH⁺ + H⁺	−10.08	–9.80 ± 0.10	−9.81 ± 0.10
Cd²⁺ + 2 H₂O ⇌ Cd(OH)₂ + 2 H⁺	–20.35	–20.19 ± 0.13	−20.6 ± 0.4
Cd²⁺ + 3 H₂O ⇌ Cd(OH)₃^– + 3 H⁺	<–33.3	–33.5 ± 0.5	−33.5 ± 0.5
Cd²⁺ + 4 H₂O ⇌ Cd(OH)₄^2– + 4 H⁺	–47.35	–47.28 ± 0.15	−47.25 ± 0.15
2 Cd²⁺ + H₂O ⇌ Cd₂OH³⁺ + H⁺	–9.390	–8.73 ± 0.01	−8.74 ± 0.10
4 Cd²⁺ + 4 H₂O ⇌ Cd₄(OH)₄⁴⁺ + H⁺	–32.85
Cd(OH)₂(s) ⇌ Cd²⁺ + 2 OH^–		–14.28 ± 0.12
Cd(OH)₂(s) + 2 H⁺ ⇌ Cd²⁺ + 2 H₂O	13.65	13.72 ± 0.12	13.71 ± 0.12

Calcium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[16]	Nordstrom et al., 1990^[17]	Brown and Ekberg, 2016^[27]
Ca²⁺ + H₂O ⇌ CaOH⁺ + H⁺	–12.85	–12.78	–12.57 ± 0.03
Ca(OH)₂(cr) + 2 H⁺ ⇌ Ca²⁺ + 2 H₂O	22.80	22.8	22.75 ± 0.02

Californium(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Brown and Ekberg, 2016^[19]
Cf³⁺ + 3 H₂O ⇌ Bk(OH)₃(s) + 3 H⁺	–13.0 ± 1.0

Cerium(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[28]	NIST46^[4]	Brown and Ekberg, 2016^[29]
Ce³⁺ + H₂O ⇌ CeOH²⁺ + H⁺	–8.3	–8.3	–8.31 ± 0.03
2 Ce³⁺ + 2 H₂O ⇌ Ce₂(OH)₂⁴⁺ + 2 H⁺			–16.0 ± 0.2
3 Ce³⁺ + 5 H₂O ⇌ Ce₃(OH)₅⁴⁺ + 5 H⁺			–34.6 ± 0.3
Ce(OH)₃(s) + 3 H⁺ ⇌ Ce³⁺ + 3 H₂O			18.5 ± 0.5
Ce(OH)₃(s) ⇌ Ce³⁺ + 3 OH^–		–22.1 ± 0.9

Chromium(II)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K (The divalent state is unstable in water, producing hydrogen whilst being oxidised to a higher valency state (Baes and Mesmer, 1976). The reliability of the data is in doubt.):


Reaction	NIST46^[4]	Ball and Nordstrom, 1988^[30]
Cr²⁺ + H₂O ⇌ CrOH⁺ + H⁺	–5.5
Cr(OH)₂(s) ⇌ Cr²⁺ + 2 OH^–		–17 ± 0.02

Chromium(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[31]	Rai et al., 1987^[32]	Ball and Nordstrom, 1988^[30]	Brown and Ekberg, 2016^[33]
Cr³⁺ + H₂O ⇌ CrOH²⁺ + H⁺	–4.0	–3.57 ± 0.08		–3.60 ± 0.07
Cr³⁺ + 2 H₂O ⇌ Cr(OH)₂⁺ + 2 H⁺	–9.7	–9.84		–9.65 ± 0.20
Cr³⁺ + 3 H₂O ⇌ Cr(OH)₃ + 3 H⁺	–18	–16.19		–16.25 ± 0.19
Cr³⁺ + 4 H₂O ⇌ Cr(OH)₄^- + 4 H⁺	–27.4	–27.65 ± 0.12		–27.56 ± 0.21
2 Cr³⁺ + 2 H₂O ⇌ Cr₂(OH)₂⁴⁺ + 2 H⁺	–5.06	–5.0		–5.29 ± 0.16
3 Cr³⁺ + 4 H₂O ⇌ Cr₃(OH)₄⁵⁺ + 4 H⁺	–8.15	–10.75 ± 0.15		–9.10 ± 0.14
Cr(OH)₃(s) + 3 H⁺ ⇌ Cr³⁺ + 3 H₂O	12		9.35	9.41 ± 0.17
Cr₂O₃(s) + 6 H⁺ ⇌ 2 Cr³⁺ + 3 H₂O			8.52
CrO_1.5(s) + 3 H⁺ ⇌ Cr³⁺ + 1.5 H₂O				7.83 ± 0.10

Chromium(VI)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[34]	Ball and Nordstrom, 1998^[30]
CrO₄^2– + H⁺ ⇌ HCrO₄^–	6.51	6.55 ± 0.04
HCrO₄^– + H⁺ ⇌ H₂CrO₄	–0.20
CrO₄²– + 2 H⁺ ⇌ H₂CrO₄		6.31
2 HCrO₄^– ⇌ Cr₂O₇^2– + H₂O	1.523
2 CrO₄^2– + 2 H⁺ ⇌ Cr₂O₇^2– + H₂O		14.7 ± 0.1

Cobalt(II)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[35]	Brown and Ekberg, 2016^[36]
Co²⁺ + H₂O ⇌ CoOH⁺ + H⁺	–9.65	−9.61 ± 0.17
Co²⁺ + 2 H₂O ⇌ Co(OH)₂ + 2 H⁺	–18.8	−19.77 ± 0.11
Co²⁺ + 3 H₂O ⇌ Co(OH)₃^– + 3 H⁺	–31.5	−32.01 ± 0.33
Co²⁺ + 4 H₂O ⇌ Co(OH)₄^2– + 4 H⁺	–46.3
2 Co²⁺ + H₂O ⇌ Co₂(OH)₃⁺ + H⁺	–11.2
4 Co²⁺ + 4 H₂O ⇌ Co₄(OH)₄⁴⁺ + 4H⁺	–30.53
Co(OH)₂(s) + 2 H⁺ ⇌ Co²⁺ + 2 H₂O	12.3	13.24 ± 0.12
CoO(s) + 2 H⁺ ⇌ Co²⁺ + H₂O		13.71 ± 0.10

Cobalt(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Brown and Ekberg, 2016^[37]
Co³⁺ + H₂O ⇌ CoOH²⁺ + H⁺	−1.07 ± 0.11

Copper(I)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Brown and Ekberg, 2016^[38]
Cu⁺ + H₂O ⇌ CuOH + H⁺	–7.8 ± 0.4
Cu⁺ + 2 H₂O ⇌ Cu(OH)₂^– + 2 H⁺	–18.6 ± 0.6

Copper(II)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[39]	NIST46^[4]	Plyasunova et al., 1997^[40]	Powell et al., 2007^[41]	Brown and Ekberg, 2016^[38]
Cu²⁺ + H₂O ⇌ CuOH⁺ + H⁺	< –8	–7.7	–7.97 ± 0.09	–7.95 ± 0.16	–7.64 ± 0.17
Cu²⁺ + 2 H₂O ⇌ Cu(OH)₂ + 2 H⁺	(< –17.3)	–17.3	–16.23 ± 0.15	–16.2 ± 0.2	–16.24 ± 0.03
Cu²⁺ + 3 H₂O ⇌ Cu(OH)₃^– + 3 H⁺	(< –27.8)	–27.8	–26.63 ± 0.40	–26.60 ± 0.09	–26.65 ± 0.13
Cu²⁺ + 4 H₂O ⇌ Cu(OH)₄^2– + 4 H⁺	–39.6	–39.6	–39.73 ± 0.17	–39.74 ± 0.18	–39.70 ± 0.19
2 Cu²⁺ + H₂O ⇌ Cu₂(OH)₃⁺ + H⁺			–6.71 ± 0.30	–6.40 ± 0.12	–6.41 ± 0.17
2 Cu²⁺ + 2 H₂O ⇌ Cu₂(OH)₂²⁺ + 2 H⁺	–10.36	–10.3	–10.55 ± 0.17	–10.43 ± 0.07	–10.55 ± 0.02
3 Cu²⁺ + 4 H₂O ⇌ Cu₃(OH)₄²⁺ + 4 H⁺			–20.95 ± 0.30	–21.1 ± 0.2	–21.2 ± 0.4
CuO(s) + 2 H⁺ ⇌ Cu²⁺ + H₂O	7.62		7.64 ± 0.06	7.64 ± 0.06	7.63 ± 0.05
Cu(OH)₂(s) + 2 H⁺ ⇌ Cu²⁺ + 2 H₂O				8.67 ± 0.05	8.68 ± 0.10

Curium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Brown and Ekberg, 2016^[42]
Cm³⁺ + H₂O ⇌ Cm(OH)²⁺ + H⁺	−7.66 ± 0.07
Cm³⁺ + 2 H₂O ⇌ Cm(OH)₂⁺ + 2 H⁺	−15.9 ± 0.1
Cm³⁺ + 3 H₂O ⇌ Cm(OH)₃(s) + 3 H⁺	−13.9 ± 0.4

Dysprosium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[28]	Brown and Ekberg, 2016^[43]
Dy³⁺ + H₂O ⇌ DyOH²⁺ + H⁺	−8.0	−7.53 ± 0.14
Dy³⁺ + 2 H₂O ⇌ Dy(OH)₂⁺ + 2 H⁺	(–16.2)
Dy³⁺ + 3 H₂O ⇌ Dy(OH)₃ + 3 H⁺	(–24.7)
Dy³⁺ + 4 H₂O ⇌ Dy(OH)₄⁻ + 4 H⁺	–33.5
2 Dy³⁺ + 2 H₂O ⇌ Dy₂(OH)₂⁴⁺ + 2 H⁺		−13.76 ± 0.20
3 Dy³⁺ + 5 H₂O ⇌ Dy₃(OH)₅⁴⁺ + 5 H⁺		−30.6 ± 0.3
Dy(OH)₃(s) + 3 H⁺ ⇌ Dy³⁺ + 3 H₂O	15.9	16.26 ± 0.30
Dy(OH)₃(c) + OH⁻ ⇌ Dy(OH)₄⁻	−3.6
Dy(OH)₃(c) ⇌ Dy(OH)₃	−8.8

Erbium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[28]	Brown and Ekberg, 2016^[44]
Er³⁺ + H₂O ⇌ ErOH²⁺ + H⁺	−7.9	−7.46 ± 0.09
Er³⁺ + 2 H₂O ⇌ Er(OH)₂⁺ + 2 H⁺	(−15.9)
Er³⁺ + 3 H₂O ⇌ Er(OH)₃ + 3 H⁺	(−24.2)
Er³⁺ + 4 H₂O ⇌ Er(OH)₄⁻ + 4 H⁺	−32.6
2 Er³⁺ + 2 H₂O ⇌ Er₂(OH)₂⁴⁺ + 2 H⁺	−13.65	−13.50 ± 0.20
3 Er³⁺ + 5 H₂O ⇌ Er₃(OH)₅⁴⁺ + 5 H⁺	<−29.3	−31.0 ± 0.3
Er(OH)₃(s) + 3 H⁺ ⇌ Er³⁺ + 3 H₂O	15.0	15.79 ± 0.30
Er(OH)₃(c) + OH⁻ ⇌ Er(OH)₄⁻	−3.6
Er(OH)₃(c) ⇌ Er(OH)₃	~ −9.2

Europium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[28]	NIST46^[4]	Hummel et al., 2002^[45]	Brown and Ekberg, 2016^[29]
Eu³⁺ + H₂O ⇌ EuOH²⁺ + H⁺	–7.8		–7.64 ± 0.04	–7.66 ± 0.05
Eu³⁺ + 2 H₂O ⇌ Eu(OH)₂⁺ + 2 H⁺			–15.1 ± 0.2
Eu³⁺ + 3 H₂O ⇌ Eu(OH)₃ + 3 H⁺			–23.7 ± 0.1
Eu³⁺ + 4 H₂O ⇌ Eu(OH)₄⁻ + 4 H⁺			–36.2 ± 0.5
2 Eu³⁺ + 2 H₂O ⇌ Eu₂(OH)₂⁴⁺ + 2 H⁺			-	–14.1 ± 0.2
3 Eu³⁺ + 5 H₂O ⇌ Eu₃(OH)₅⁴⁺ + 5 H⁺			-	–32.0 ± 0.3
Eu(OH)₃(s) + 3 H⁺ ⇌ Eu³⁺ + 3 H₂O	17.5		17.6 ± 0.8 (am) 14.9 ± 0.3 (cr)	16.48 ± 0.30
Eu(OH)₃(s) ⇌ Eu³⁺ + 3 OH^–		–24.5 ± 0.7 (am) –26.5 (cr)

Gadolinium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[46]	Brown and Ekberg, 2016^[47]
Gd³⁺ + H₂O ⇌ GdOH²⁺ + H⁺	–8.0	–7.87 ± 0.05
Gd³⁺ + 2 H₂O ⇌ Gd(OH)₂⁺ + 2 H⁺	(–16.4)
Gd³⁺ + 3 H₂O ⇌ Gd(OH)₃ + 3 H⁺	(–25.2)
Gd³⁺ + 4 H₂O ⇌ Gd(OH)₄^– + 4 H⁺	–34.4
2 Gd³⁺ + 2 H₂O ⇌ Gd₂(OH)₂⁴⁺ + 2 H⁺		–14.16 ± 0.20
3 Gd³⁺ + 5 H₂O ⇌ Gd₃(OH)₅⁴⁺ + 5 H⁺		–33.0 ± 0.3
Gd(OH)₃(s) + 3 H⁺ ⇌ Gd³⁺ + 3 H₂O	15.6	17.20 ± 0.48
Gd(OH)₃(c) + OH^– ⇌ Gd(OH)₄^–	–4.8
Gd(OH)₃(c) ⇌ Gd(OH)₃	–9.6

Gallium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[48]	Smith et al., 2003^[49]	Brown and Ekberg, 2016^[50]
Ga³⁺ + H₂O ⇌ GaOH²⁺ + H⁺	–2.6	–2.897	–2.74
Ga³⁺ + 2 H₂O ⇌ Ga(OH)₂⁺ + 2 H⁺	–5.9	–6.694	–7.0
Ga³⁺ + 3 H₂O ⇌ Ga(OH)₃ + 3 H⁺	–10.3		–11.96
Ga³⁺ + 4 H₂O ⇌ Ga(OH)₄^– + 4 H⁺	–16.6	–16.588	–15.52
Ga(OH)₃(s) ⇌ Ga³⁺ + 3 OH^–	$\approx$ –37	–37.0
GaO(OH)(s) + H₂O ⇌ Ga³⁺ + 3 OH^–	–39.06	–39.1	–40.51

Germanium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[51]	Wood and Samson, 2006^[52]	Filella and May, 2023^[53]
Ge(OH)₄ ⇌ GeO(OH)₃^- + H⁺	–9.31	–9.32 ± 0.05	–9.099
Ge(OH)₄ ⇌ GeO2(OH)₂²⁺ + 2 H⁺	–21.9
GeO₂(OH)₂^2– + H⁺ ⇌ GeO(OH)₃^–			12.76
8 Ge(OH)₄ ⇌ Ge₈O₁₆(OH)₃^3- + 13 H₂O + 3 H⁺	–14.24
8 Ge(OH)₄ + 3 OH^– ⇌ Ge₈(OH)₃₅^3–			28.33
GeO₂(s, hexa) + 2 H₂O ⇌ Ge(OH)₄		–1.35	–1.373
GeO₂(s, tetra) + 2 H₂O ⇌ Ge(OH)₄	-4.37	–5.02	–4.999

Gold(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[54]
Au(OH)₃ +2 H⁺ ⇌ AuOH²⁺ + 2 H₂O	1.51
Au(OH)₃ + H⁺ ⇌ Au(OH)₂⁺ + H₂O	< 1.0
Au(OH)₃ + H₂O ⇌ Au(OH)₄^– + H⁺	–11.77
Au(OH)₃ + 2 H₂O ⇌ Au(OH)₅^2– + 2 H⁺	–25.13
Au(OH)₅^2– + 3 H₂O ⇌ Au(OH)₆³– + 3 H⁺	< –41.1
Au(OH)₃(c) ⇌ Au(OH)₃	–5.51

Hafnium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[55]	Brown and Ekberg, 2016^[56]
Hf⁴⁺ + H₂O ⇌ HfOH³⁺ + H⁺	–0.25	−0.26 ± 0.10
Hf⁴⁺ + 2 H₂O ⇌ Hf(OH)₂²⁺ + 2 H⁺	(–2.4)
Hf⁴⁺ + 3 H₂O ⇌ Hf(OH)₃⁺ + 3 H⁺	(–6.0)
Hf⁴⁺ + 4 H₂O ⇌ Hf(OH)₄ + 4 H⁺	–10.7*	−3.75 ± 0.34*
Hf⁴⁺ + 5 H₂O ⇌ Hf(OH)₅^– + 5 H⁺	–17.2
3 Hf⁴⁺ + 4 H₂O ⇌ Hf₃(OH)₄⁸⁺ + 4 H⁺		0.55 ± 0.30
4 Hf⁴⁺ + 8 H₂O ⇌ Hf₄(OH)₈⁸⁺ + 8 H⁺		6.00 ± 0.30
HfO₂(s) + 4 H⁺ ⇌ Hf⁴⁺ + 2 H₂O	–1.2*	–5.56 ± 0.15*
HfO₂₍am) + 4 H⁺ ⇌ Hf⁴⁺ + 2 H₂O		–3.11 ± 0.20

*Errors in compilations concerning equilibrium and/or data elaboration. Data not recommended. Strongly suggested to refer to the original papers.

Holmium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[28]	Brown and Ekberg, 2016^[57]
Ho³⁺ + H₂O ⇌ HoOH²⁺ + H⁺	−8.0	−7.43 ± 0.05
2 Ho³⁺ + 2 H₂O ⇌ Ho₂(OH)₂⁴⁺ + 2 H⁺		−13.5 ± 0.2
3 Ho³⁺ + 5 H₂O ⇌ Ho₃(OH)₅⁴⁺ + 5 H⁺		−30.9 ± 0.3
Ho(OH)₃(s) + 3 H⁺ ⇌ Ho³⁺ + 3 H₂O	15.4	15.60 ± 0.30

Indium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[58]	NIST46^[4]	Brown and Ekberg, 2016^[59]
In³⁺ + H₂O ⇌ InOH²⁺ + H⁺	–4.00	–3.927	–3.96
In³⁺ + 2 H₂O ⇌ In(OH)₂⁺ + 2 H⁺	–7.82	–7.794	–9.16
In³⁺ + 3 H₂O ⇌ In(OH)₃ + 3 H⁺	–12.4	–12.391
In³⁺ + 4 H₂O ⇌ In(OH)₄^– + 4 H⁺	–22.07	–22.088	–22.05
In(OH)₃(s) ⇌ In³⁺ + 3 OH^–	–36.92	–36.9	–36.92
1/2 In₂O₃(s) + 3/2 H₂O ⇌ In³⁺ + 3 OH^–			–35.24

Iridium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Brown and Ekberg, 2016^[60]
Ir³⁺ + H₂O ⇌ IrOH²⁺ + H⁺	‒3.77 ± 0.10
Ir³⁺ + 2 H₂O ⇌ Ir(OH)₂⁺ + 2 H⁺	‒8.46 ± 0.20
Ir(OH)₃(s) + 3 H⁺ ⇌ Ir³⁺ + 3 H₂O	8.88 ± 0.20

Iron(II)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[61]	Nordstrom et al., 1990^[17]	Hummel et al., 2002^[45]	Lemire et al., 2013^[62]	Brown and Ekberg, 2016^[63]
Fe²⁺ + H₂O ⇌ FeOH⁺ + H⁺	–9.3	–9.5	–9.5	–9.1 ± 0.4	−9.43 ± 0.10
Fe²⁺ + 2 H₂O ⇌ Fe(OH)₂ + 2 H⁺	–20.5				−20.52 ± 0.08
Fe²⁺ + 3 H₂O ⇌ Fe(OH)₃^- + 3 H⁺	–29.4				−32.68 ± 0.15
Fe(OH)₂(s) +2 H⁺ ⇌ Fe²⁺ + 2 H₂O					12.27 ± 0.88

Iron(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[61]	Lemire et al., 2013^[62]	Brown and Ekberg, 2016^[64]
Fe³⁺ + H₂O ⇌ FeOH²⁺ + H⁺	–2.19	−2.15 ± 0.07	–2.20 ± 0.02
Fe³⁺ + 2 H₂O ⇌ Fe(OH)₂⁺ + 2 H⁺	–5.67	−4.8 ± 0.4	–5.71 ± 0.10
Fe³⁺ + 3 H₂O ⇌ Fe(OH)₃ + 3 H⁺	<–12	<–14	–12.42 ± 0.20
Fe³⁺ + 4 H₂O ⇌ Fe(OH)₄^– + 4 H⁺	–21.6	−21.5 ± 0.5	–21.60 ± 0.23
2 Fe³⁺ + 2 H₂O ⇌ Fe₂(OH)₂⁴⁺ + 2 H⁺	–2.95	–2.91 ± 0.07	–2.91 ± 0.07
3 Fe³⁺ + 4 H₂O ⇌ Fe₃(OH)₄⁵⁺ + 4 H⁺	–6.3		−6.3 ± 0.1
Fe(OH)₃(s) +3 H⁺ ⇌ Fe3⁺ + 3 H₂O 2-line ferrihydrite	2.5	3.5	3.50 ± 0.20
Fe(OH)₃(s) ⇌ Fe³⁺ + 3 OH⁻ 6-line ferrihydrite		−38.97 ± 0.64
α-FeOOH(s)+ 3 H⁺ ⇌ Fe³⁺ + 2 H₂O goethite	0.5		0.33 ± 0.10
α-FeOOH + H₂O ⇌ Fe³⁺ + 3 OH⁻ goethite		−41.83 ± 0.37
0.5 α-Fe₂O₃(s)+ 3 H⁺ ⇌ Fe³⁺ + 1.5 H₂O hematite			0.36 ± 0.40
0.5 α-Fe₂O₃ + 1.5 H₂O ⇌ Fe³⁺ + 3 OH⁻ hematite		−42.05 ± 0.26
0.5 γ-Fe₂O₃(s) + 3 H⁺ ⇌ Fe³⁺ + 1.5 H₂O maghemite			1.61 ± 0.61
0.5 γ-Fe₂O₃ + 1.5 H₂O ⇌ Fe³⁺ + 3 OH⁻ maghemite		−40.59 ± 0.29
α-FeOOH(s)+ 3 H⁺ ⇌ Fe³⁺ + 2 H₂O lepidocrocite			1.85 ± 0.37
γ-FeOOH + H₂O ⇌ Fe³⁺ + 3 OH⁻ lepidocrocite		−40.13 ± 0.37
Fe(OH)₃(s) + 3 H⁺ ⇌ Fe³⁺ + 3 H₂O magnetite			−12.26 ± 0.26

Lanthanum

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[65]	Brown and Ekberg, 2016^[66]
La³⁺ + H₂O ⇌ LaOH²⁺ + H⁺	–8.5	–8.89 ± 0.10
2 La³⁺ + 2 H₂O ⇌ La₂(OH)₂⁴⁺ + 2 H⁺	≤ –17.5	–17.57 ± 0.20
3 La³⁺ + 5 H₂O ⇌ La₃(OH)₅⁴⁺ + 5 H⁺	≤ –38.3	–37.8 ± 0.3
5 La³⁺ + 9 H₂O ⇌ La₅(OH)₉⁶⁺ + 9 H⁺	–71.2
La(OH)₃(s) + 3 H⁺ ⇌ La³⁺ + 3 H₂O	20.3	19.72 ± 0.34

Lead(II)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[67]	NIST46^[4]	Powell et al, 2009^[68]	Brown and Ekberg, 2016^[69]	Cataldo et al., 2018^[70]
Pb²⁺ + H₂O ⇌ PbOH+ + H⁺	–7.71	–7.6	–7.46 ± 0.06	–7.49 ± 0.13	–6.47± 0.03
Pb²⁺ + 2 H₂O ⇌ Pb(OH)₂ + 2 H⁺	–17.12	–17.1	–16.94 ± 0.09	–16.99 ± 0.06	–16.12 ± 0.01
Pb²⁺ + 3 H₂O ⇌ Pb(OH)^3- + 3 H⁺	–28.06	–28.1	–28.03± 0.06	–27.94 ± 0.21	–28.4 ± 0.1
Pb²⁺ + 4 H₂O ⇌ Pb(OH)₄^2- + 4 H⁺			–40.8
2 Pb²⁺ + H₂O ⇌ Pb₂(OH)₃⁺ + H⁺	–6.36	–6.4	–7.28± 0.09	–6.73 ± 0.31
3 Pb²⁺ + 4 H₂O ⇌ Pb₃₍OH)₄²⁺ + 4 H⁺	–23.88	–23.9	–23.01 ± 0.07	–23.43 ± 0.10
3 Pb²⁺ + 5 H₂O ⇌ Pb₃(OH)₅⁺ + 5 H⁺				–31.11 ± 0.10
4 Pb²⁺ + 4 H₂O ⇌ Pb₄(OH)₄⁴⁺ + 4 H⁺	–20.88	–20.9	–20.57± 0.06	–20.71 ± 0.18
6 Pb²⁺ + 8 H₂O ⇌ Pb₆(OH)₈⁴⁺ + 8 H⁺	–43.61	–43.6	–42.89± 0.07	–43.27 ± 0.47
PbO(s) + 2 H⁺ ⇌ Pb²⁺ + H₂O			12.62 (red) 12.90 (yellow)
PbO(s) +H2O ⇌ Pb²⁺ + 2 OH^–	–15.28 (red)	-15.3	–15.3 (red) –15.1 (yellow)	–15.37 ± 0.04 (red) –15.1 ± 0.08 (yellow)
Pb₂O(OH)₂₍s) +H2O ⇌ 2 Pb²⁺ + 4 OH^–			–14.9
PbO(s) +H₂O ⇌ Pb(OH)₂			–4.4 (red) –4.2 (yellow)
Pb₂O(OH)₂(s) +H₂O ⇌ 2 Pb(OH)₂			–4.0
PbO(s) + 2 H₂O ⇌ Pb(OH)₃^– + H⁺			–1.4 (red) –1.2 (yellow)
Pb₂O(OH)₂₍s) + 2 H₂O ⇌ 2 Pb(OH)₃^– + 2 H⁺			–1.0

Lead(IV)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Feitknecht and Schindler, 1963^[71]
β-PbO₂ + 2 H₂O ⇌ Pb⁴⁺ + 4 OH^–	–64
β-PbO₂ + 2 H₂O + 2 OH^– ⇌ Pb(OH)₆^2–	–4.5

Lithium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[72]	Nordstrom et al., 1990^[17]	Brown and Ekberg, 2016^[73]
Li⁺ + H₂O ⇌ LiOH + H⁺	–13.64	–13.64	–13.84 ± 0.14

Magnesium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[74]	Nordstrom et al., 1990^[17]	Brown and Ekberg, 2016^[75]
Mg²⁺ + H₂O ⇌ MgOH⁺ + H⁺	–11.44	–11.44	–11.70 ± 0.04
4 Mg²⁺ + 4 H₂O ⇌ Mg₄(OH)₄⁴⁺ + 4 H⁺	–39.71
Mg(OH)₂(cr) + 2 H⁺ ⇌ Mg²⁺ + 2 H₂O	16.84	16.84	17.11 ± 0.04

Manganese(II)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Perrin et al., 1969^[76]	Baes and Mesmer, 1976^[77]	Nordstrom et al., 1990^[17]	Hummel et al., 2002^[45]	Brown and Ekberg, 2016^[78]
Mn²⁺ + H₂O ⇌ MnOH⁺ + H⁺	–10.59	–10.59	–10.59	–10.59	−10.58 ± 0.04
Mn²⁺ + 2 H₂O ⇌ Mn(OH)₂ + 2 H⁺		–22.2			−22.18 ± 0.20
Mn²⁺ + 3 H₂O ⇌ Mn(OH)₃^– + 3 H⁺		–34.8			−34.34 ± 0.45
Mn²⁺ + 4 H₂O ⇌ Mn(OH)₄^2– + 4 H⁺		–48.3			−48.28 ± 0.40
2 Mn²⁺ + H₂O ⇌ Mn₂OH³⁺ + H⁺		–10.56
2 Mn²⁺ + 3 H₂O ⇌ Mn₂(OH)₃⁺ + 6 H⁺		–23.90
Mn(OH)₂(s) + 2 H⁺ ⇌ Mn²⁺ + 2 H₂O	15.2	15.2	15.2		15.19 ± 0.10
MnO(s) + 2 H⁺ ⇌ Mn²⁺ + H₂O					17.94 ± 0.12

Manganese(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Brown and Ekberg, 2016^[79]
Mn³⁺ + H₂O ⇌ MnOH²⁺ + H⁺	–11.70 ± 0.04

Mercury(I)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[80]	Brown and Ekberg, 2016^[81]
Hg₂²⁺ + H₂O ⇌ Hg₂OH⁺ + H⁺	−5.0^a	−4.45 ± 0.10

(^a) 0.5 M HClO₄

Mercury(II)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[82]	Powell et all, 2005^[83]	Brown and Ekberg, 2016^[79]
Hg²+ + H₂O ⇌ HgOH+ + H⁺	−3.40	–3.40 ± 0.08	–3.40 ± 0.08
Hg²⁺ + 2 H₂O ⇌ Hg(OH)₂ + 2 H⁺	-6.17	–5.98 ± 0.06	−5.96 ± 0.07
Hg²⁺ + 3 H₂O ⇌ Hg(OH)₃^– + 3 H⁺	–21.1	–21.1 ± 0.3
HgO(s) + 2 H⁺ ⇌ Hg²⁺ + H₂O	2.56	2.37 ± 0.08	2.37 ± 0.08

Molybdenum(VI)

Hydrolysis constants (log values) in critical compilations at infinite dilution, T = 298.15 K and I = 3 M NaClO₄ (^a) or 0.1 M Na⁺ medium, Data at I = 0 are not available (^b):


Reaction	Baes and Mesmer, 1976^[84]	Jolivet, 2000^[85]	NIST46^[4]	Crea et al., 2017^[86]
MoO₄^2– + H⁺ ⇌ HMoO₄^–	3.89^a		4.24	4.47 ± 0.02
MoO₄^2– + 2 H⁺ ⇌ H₂MoO₄	7.50^a			8.12 ± 0.03
HMoO₄^– + H⁺ ⇌ H₂MoO₄			4.0
Mo₇O₂₄^6– + H⁺ ⇌ HMo₇O₂₄^5–		4.4
HMo₇O₂₄^5– + H⁺ ⇌ H₂Mo7O₂₄^4–		3.5
H₂Mo₇O₂₄^4– + H⁺ ⇌ H₃Mo₇O₂₄^3–		2.5
7 MoO₄^2-+ 8 H⁺ ⇌ Mo₇O₂₄^6– + 4 H₂O	57.74^a		52.99^b	51.93 ± 0.04
7 MoO₄^2– + 9 H⁺ ⇌ Mo₇O₂₃(OH)^5– + 4 H₂O	62.14^a			58.90 ± 0.02
7 MoO₄^2– + 10 H⁺ ⇌ Mo₇O₂₂(OH)₂^4– + 4 H₂O	65.68^a			64.63 ± 0.05
7 MoO₄^2– + 11 H⁺ ⇌ Mo₇O₂₁(OH)₃^3– + 4 H₂O	68.21^a			68.68 ± 0.06
19 MoO₄^2- + 34 H⁺ ⇌ Mo₁₉O₅₉^4– + 17 H₂O	196.3^a		196^a
MoO₃(s) + H₂O ⇌ MoO₄^2– + 2 H⁺	–12.06^a

Neodymium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[28]	NIST46^[4]	Neck et al., 2009^[87]	Brown and Ekberg, 2016^[29]
Nd³⁺ + H₂O ⇌ NdOH²⁺ + H⁺	–8.0	–8.0	–7.4 ± 0.4	–8.13 ± 0.05
Nd³⁺ + 2 H₂O ⇌ Nd(OH)₂⁺ + 2 H⁺	(–16.9)		–15.7 ± 0.7
Nd³⁺ + 3 H₂O ⇌ Nd(OH)₃(aq) + 3 H⁺	(–26.5)		–26.2 ± 0.5
Nd³⁺ + 4 H₂O ⇌ Nd(OH)₄⁻ + 4 H⁺	(–37.1)	–37.4	–40.7 ± 0.7
2 Nd³⁺ + 2 H₂O ⇌ Nd₂(OH)₂⁴⁺ + 2 H⁺	–13.86	–13.9		–15.56 ± 0.20
3 Nd³⁺ + 5 H₂O ⇌ Nd₃(OH)₅⁴⁺ + 5 H⁺	< –28.5			–34.2 ± 0.3
Nd(OH)₃(s) + 3 H⁺ ⇌ Nd³⁺ + 3 H₂O	18.6		17.2 ± 0.4	17.89 ± 0.09
Nd(OH)₃(s) ⇌ Nd³⁺ + 3 OH^–		–23.2 ± 0.9	–21.5 (act) –23.1(inact)

Neptunium(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Brown and Ekberg, 2016^[88]	Grenthe et al, 2020^[6]
Np³⁺ + H₂O ⇌ NpOH²⁺ + H⁺	-7.3 ± 0.5	–6.8 ± 0.3

Neptunium(IV)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[89]	NIST46^[4]	Brown and Ekberg, 2016^[90]	Grenthe et al, 2020^[6]
Np⁴⁺ + H₂O ⇌ NpOH³⁺ + H⁺	–1.49	–1.5	–1.31 ± 0.05	0.5 ± 0.2
Np⁴⁺ + 2 H₂O ⇌ Np(OH)₂²⁺ + 2 H⁺			–3.7 ± 0.3	0.3 ± 0.3
Np⁴⁺ + 4 H₂O ⇌ Np(OH)₄ + 4 H⁺			–10.0 ± 0.9	–8 ± 1
Np⁴⁺ + 4 OH^- ⇌ NpO₂(am, hyd) + 2 H₂O	52	54.9 ± 0.4	57.5 ± 0.3	56.7 ± 0.5

Neptunium(V)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[89]	Brown and Ekberg, 2016^[91]	Grenthe et al, 2020^[6]
NpO₂⁺ + + H₂O ⇌ NpO₂(OH) + H⁺	–8.85	–10.7 ± 0.5	–11.3 ± 0.7
NpO₂⁺ + 2 H₂O ⇌ NpO₂(OH)₂^- + 2 H⁺		–22.8 ± 0.7	–23.6 ± 0.5
NpO₂⁺ + H₂O ⇌ NpO₂(OH)(am, fresh) + H⁺	≤ –4.7	–5.21 ± 0.05	–5.3 ± 0.2
NpO₂⁺ + H₂O ⇌ NpO₂(OH)(am, aged) + H⁺		–4.53 ± 0.06	–4.7 ± 0.5

Neptunium(VI)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[92]	NIST46^[4]	Brown and Ekberg, 2016^[93]	Grenthe et al, 2020^[6]
NpO₂²⁺ + H₂O ⇌ NpO₂(OH)⁺ + H⁺	–5.15	–5.12	–5.1 ± 0.2	–5.1 ± 0.4
NpO₂²⁺ + 3 H₂O ⇌ NpO₂(OH)₃^- + 3 H⁺			–21 ± 1
NpO₂²⁺ + 4 H₂O ⇌ NpO₂(OH)₄^2- + 4 H⁺			–32 ± 1
2 NpO₂²⁺ + 2 H₂O ⇌ (NpO₂)₂(OH)₂²⁺ + 2 H⁺	–6.39	–6.39	–6.2 ± 0.2	–6.2 ± 0.2
3 NpO₂²⁺ + 5 H₂O ⇌ (NpO₂)₃(OH)₅⁺ + 5 H⁺	–17.49	–17.49	–17.0 ± 0.2	–17.1 ± 0.2
NpO₂²⁺ + 2 H₂O ⇌ NpO₃.H₂O(cr) + 2 H⁺	≥-6.6		–5.4 ± 0.4	–5.4 ± 0.4

Nickel(II)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Feitknecht and Schindler, 1963^[71]	Baes and Messmer, 1976^[94]	NIST46^[4]	Gamsjäger et al., 2005^[95]	Thoenen et al., 2014^[96]	Brown and Ekberg, 2016^[97]
Ni²⁺ + H₂O ⇌ NiOH⁺ + H⁺		–9.86	–9.9	–9.54 ± 0.14	–9.54 ± 0.14	–9.90 ± 0.03
Ni²⁺ + 2 H₂O ⇌ Ni(OH)₂ + 2 H⁺		–19	–19		< –18	–21.15 ± 0.0
Ni²⁺ + 3 H₂O ⇌ Ni(OH)₃^– + 3 H⁺		–30	–30	–29.2 ± 1.7	–29.2 ± 1.7
Ni²⁺ + 4 H₂O ⇌ Ni(OH)₄^2– + 4 H⁺		< –44
2 Ni²⁺ + H₂O ⇌ Ni₂(OH)³⁺ + H⁺		–10.7		–10.6 ± 1.0	–10.6 ± 1.0	–10.6 ± 1.0
4 Ni²⁺ + 4 H₂O ⇌ Ni₄(OH)₄⁴⁺ + 4 H⁺		–27.74	–27.7	–27.52 ± 0.15	–27.52 ± 0.15	–27.9 ± 0.6
β-Ni(OH)₂(s) + 2 H⁺ ⇌ Ni²⁺ + 2 H₂O		10.8			11.02 ± 0.20	10.96 ± 0.20 11.75 ± 0.13 (microcr)
Ni(OH)₂(s) ⇌ Ni²⁺ + 2 OH^–	–17.2 (inactive)		–17.2	–16.97± 0.20 (β) –17.2 ± 1.3 (cr)
Ni(OH)₂(s) + OH^– ⇌ Ni(OH)₃^–	–4.2 (inactive)
NiO(cr) + 2 H⁺ ⇌ Ni²⁺ + H₂O				12.38 ± 0.06		12.48 ± 0.15

Niobium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[72]	Filella and May, 2020^[98]
Nb(OH)₅ + H⁺ ⇌ Nb(OH)₄⁺ + H₂O	~ –0.6	1.603
Nb(OH)₅ + H₂O ⇌ Nb(OH)₆^– + H⁺	~ –4.8	–4.951
Nb₆O₁₉^8– + H⁺ ⇌ HNb₆O₁₉^7–		14.95
HNb₆O₁₉^7– + H⁺ ⇌ H₂Nb₆O₁₉^6–		13.23
H₂Nb₆O₁₉^6– + H⁺ ⇌ H₃Nb₆O₁₉^5–		11.73
1/2 Nb₂O₅(act) + 5/2 H₂O ⇌ Nb(OH)₅	~ –7.4
Nb(OH)₅(am,s) ⇌ Nb(OH)₅		–7.510
Nb₂O₅(s) + 5 H₂O ⇌ 2 Nb(OH)₅		–18.31

Osmium(VI)

Hydrolysis constants (log values) in critical compilations at infinite dilution, I = 0.1 M and T = 298.15 K:


Reaction	Galbács et al., 1983^[99]
OsO₂(OH)₄^2– + H⁺ ⇌ HOsO₂(OH)₄^–	10.4
HOsO₂(OH)₄^– + H⁺ ⇌ H₂OsO₂(OH)₄	8.5

Osmium(VIII)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Galbács et al., 1983^[99]
OsO₂(OH)₃(O^-)aq + H⁺ ⇌ OsO₂(OH)₄aq	12.2^a
OsO₂(OH)₂(O^-)₂aq + H⁺ ⇌ OsO₂(OH)₃(O^-)aq	14.4^b

(^a) At I = 0.1 M (^b) At I = 2.5 M

Palladium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Perrin et al., 1969^[100]	Hummel et al., 2002^[45]	Kitamura and Yul, 2010^[101]	Brown and Ekberg, 2016^[102]
Pd²⁺ + H₂O ⇌ PdOH⁺ + H⁺	−0.96		−0.65 ± 0.64	−1.16 ± 0.30
Pd²⁺ + 2 H₂O ⇌ Pd(OH)₂ + 2 H⁺	−2.6	−4 ± 1	−3.11 ± 0.63	−3.07 ± 0.16
Pd²⁺ + 3 H₂O ⇌ Pd(OH)₃⁻ + 3 H⁺		−15.5 ± 1	−14.20 ± 0.63
Pd(OH)₂(am) + 2 H⁺ ⇌ Pd²⁺ + 2 H₂O		−3.3 ± 1		−3.4 ± 0.2

Plutonium(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[103]	NIST46^[4]	Brown and Ekberg, 2016^[104]	Grenthe et al, 2020^[6]
Pu³⁺ + H₂O ⇌ PuOH²⁺ + H⁺		–7.0	–6.9 ± 0.2	–6.9 ± 0.3
Pu³⁺ + 3 H₂O ⇌ Pu(OH)₃(cr) + 3 H⁺	–19.65		–15.8 ± 0.8	–15 ± 1

Plutonium(IV)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[105]	NIST46^[4]	Brown and Ekberg, 2016^[106]	Grenthe et al, 2020^[6]
Pu⁴⁺ + H₂O ⇌ PuOH ³⁺ + H⁺	–0.5	–0.5	–0.7 ± 0.1	0.6 ± 0.2
Pu⁴⁺ + 2 H₂O ⇌ Pu(OH)₂²⁺ + 2 H⁺	(–2.3)			0.6 ± 0.3
Pu⁴⁺ + 3 H₂O ⇌ Pu(OH)₃⁺ + 3 H⁺	(–5.3)			–2.3 ± 0.4
Pu⁴⁺ + 4 H₂O ⇌ Pu(OH)₄ + 4 H⁺	–9.5		–12.5 ± 0.7	–8.5 ± 0.5
Pu⁴⁺ + 4 OH^- ⇌ PuO₂(am, hyd) + 2 H₂O	49.5		47.9 ± 0.4 (0w) 53.8 ± 0.5 (1w)	58.3 ± 0.5

Plutonium(V)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[107]	NIST46^[4]	Brown and Ekberg, 2016^[108]	Grenthe et al, 2020^[6]
PuO₂⁺ + H₂O ⇌ PuO₂(OH) + H⁺	–1.49	–1.5	–1.31 ± 0.05	0.5 ± 0.2
PuO2+ + H2O ⇌ PuO2(OH)(am) + H⁺			–3.7 ± 0.3	0.3 ± 0.3

Plutonium(VI)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[109]	NIST46^[4]	Brown and Ekberg, 2016^[110]	Grenthe et al, 2020^[6]
PuO₂²⁺ + H₂O ⇌ PuO₂(OH)⁺ + H⁺	–5.6	–5.6	–5.36 ± 0.09	–5.5 ± 0.5
PuO₂²⁺ + 2 H₂O ⇌ PuO₂(OH)₂ + 2 H⁺			–12.9 ± 0.2	–13 ± 1
PuO₂²⁺ + 3 H₂O ⇌ PuO₂(OH)₃^- + 3 H+				–24 ± 1
2 PuO₂²⁺ + 2 H₂O ⇌ (PuO₂)₂(OH)₂²⁺ + 2 H⁺	–8.36	–8.36	–7.8 ± 0.5	–7 ± 1
3 PuO₂²⁺ + 5 H₂O ⇌ (PuO₂)₃(OH)₅⁺ + 5 H⁺	–21.65	–21.65
PuO₂²⁺ + 2 OH^- ⇌ PuO₂(OH)₂(am, hyd)				22.8 ± 0.6

Potassium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[72]	Nordstrom et al., 1990^[17]	Brown and Ekberg, 2016^[111]
K⁺ + H₂O ⇌ KOH + H⁺	–14.46	–14.46	–14.5 ± 0.4

Praseodymium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[28]	NIST46^[4]	Brown and Ekberg, 2016^[29]
Pr³⁺ + H₂O ⇌ PrOH²⁺ + H⁺	–8.1		–8.30 ± 0.03
2 Pr³⁺ + 2 H₂O ⇌ Pr₂(OH)₂⁴+ + 2 H⁺			–16.31 ± 0.20
3 Pr³⁺ + 5 H₂O ⇌ Pr₃(OH)₅⁴⁺ + 5 H⁺			–35.0 ± 0.3
Pr(OH)₃(s) + 3 H⁺ ⇌ Pr³⁺ + 3 H₂O	19.5		18.57 ± 0.20
Pr(OH)₃(s) ⇌ Pr³⁺ + 3 OH^–		–22.3 ± 1.0

Radium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Nordstrom et al., 1990^[17]
Ra²⁺ + H₂O ⇌ RaOH⁺ + H⁺	–13.49

Rhodium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Perrin et al., 1969^[112]	Baes and Mesmer, 1976^[113]	Brown and Ekberg^[114]
Rh³⁺ + H₂O ⇌ RhOH₂⁺ + H⁺	‒3.43	‒3.4	‒3.09 ± 0.1
Rh(OH)₃(c) + OH^‒ ⇌ Rh(OH)₄^‒		‒3.9

Samarium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[28]	NIST46^[4]	Brown and Ekberg^[29]
Sm³⁺ + H₂O ⇌ SmOH²⁺ + H⁺	–7.9	–7.9	–7.84 ± 0.11
2 Sm³⁺ + 2 H₂O ⇌ Sm₂(OH)₂⁴⁺ + 2 H⁺			–14.75 ± 0.20
3 Sm³⁺ + 5 H₂O ⇌ Sm₃(OH)₅⁴⁺ + 5 H⁺			–33.9 ± 0.3
Sm(OH)₃(s) + 3H⁺ ⇌ Sm³⁺ + 3H₂O	16.5		17.19 ± 0.30
Sm(OH)₃(s) ⇌ Sm³⁺ + 3 OH^-		–23.9 ± 0.9 (am) –25.9 (cr)

Scandium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[115]	Brown and Ekberg, 2016^[116]
Sc³⁺ + H₂O ⇌ ScOH²⁺ + H⁺	–4.3	–4.16 ± 0.05
Sc³⁺ + 2 H₂O ⇌ Sc(OH)₂⁺ + 2 H⁺	–9.7	–9.71 ± 0.30
Sc³⁺ + 3 H₂O ⇌ Sc(OH)₃ + 3 H⁺	–16.1	–16.08 ± 0.30
Sc³⁺ + 4 H₂O ⇌ Sc(OH)₄^–+ 4 H⁺	–26	–26.7 ± 0.3
2 Sc³⁺ + 2 H₂O ⇌ Sc₂(OH)₂⁴⁺ + 2 H⁺	–6.0	–6.02 ± 0.10
3 Sc³⁺ + 5 H₂O ⇌ Sc₃(OH)₅⁴⁺ + 5 H⁺	–16.34	–16.33 ± 0.10
Sc(OH)₃(s) + 3 H⁺ ⇌ Sc³⁺ + 3 H₂O		9.17 ± 0.30
ScO_1.5(s) + 3 H⁺ ⇌ Sc³⁺ + 1.5 H₂O		5.53 ± 0.30
ScO(OH)(c) + 3 H⁺ ⇌ Sc³⁺ + 2 H₂O	9.4
Sc(OH)₃(c) + OH^– ⇌ Sc(OH)₄		–3.5 ± 0.2

Selenium(–II)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Olin et al., 2015^[117]	Thoenen et al., 2014^[96]
H₂Se(g) ⇌ H₂Se(aq)	–1.10 ± 0.01	–1.10 ± 0.01
H₂Se ⇌ HSe^– + H⁺	–3.85 ± 0.05	–3.85 ± 0.05
HSe^– ⇌ Se^2– + H⁺	–14.91 ± 0.20

Selenium(IV)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[118]	Olin et al., 2005^[117]	Thoenen et al., 2014^[96]
SeO₃^2– + H⁺ ⇌ HSeO₃^–	8.50	8.36 ± 0.23	8.36 ± 0.23
HSeO₃^– + H⁺ ⇌ H₂SeO₃	2.75	2.64 ± 0.14	2.64 ± 0.14

Selenium(VI)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[119]	Olin et al., 2005^[117]	Thoenen et al., 2014^[96]
SeO₄^2‒ + H⁺ ⇌ HSeO₄^‒	1.360	1.75 ± 0.10	1.75 ± 0.10

Silicon

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[120]	Thoenen et al., 2014^[96]
Si(OH)₄ ⇌ SiO(OH)₃^– + H⁺	–9.86	–9.81 ± 0.02
Si(OH)₄ ⇌ SiO₂(OH)₂^2– + 2 H⁺	–22.92	–23.14 ± 0.09
4 Si(OH)₄ ⇌ Si₄O₆(OH)₆^4– + 2 H⁺ + 4 H₂O	–13.44
4 Si(OH)₄ ⇌ Si₄O₈(OH)₄^4– + 4 H⁺ + 4 H₂O	–35.80	–36.3 ± 0.2
SiO₂(quartz) + 2 H₂O ⇌ Si(OH)₄	–4.0	–3.739 ± 0.087
SiO₂(am) + 2 H₂O ⇌ Si(OH)₄		–2.714

Silver

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[121]	Brown and Ekberg, 2016^[122]
Ag⁺ + H₂O ⇌ AgOH + H⁺	−12.0	−11.75 ± 0.14
Ag⁺ + 2 H₂O ⇌ Ag(OH)₂⁻ + 2 H⁺	−24.0	−24.34 ± 0.14
0.5 Ag₂O(am) + H⁺ ⇌ Ag⁺ + 0.5 H₂O	6.29	6.27 ± 0.05

Sodium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[72]	Nordstrom et al., 1990^[17]	Brown and Ekberg, 2016^[123]
Na⁺ + H₂O ⇌ NaOH + H⁺	–14.18	–14.18	–14.4 ± 0.2

Strontium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[16]	Nordstrom et al., 1990^[17]	Brown and Ekberg, 2016^[124]
Sr²⁺ + H₂O ⇌ SrOH⁺ + H⁺	–13.29	–13.29	–13.15 ± 0.05

Tantalum

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[125]	Filella and May, 2019^a^[126]
Ta(OH)₅ + H⁺ ⇌ Ta(OH)₄⁺ + H₂O	~1	0.7007
Ta(OH)₅ + H₂O ⇌ Ta(OH)₆^– + H⁺	~ –9.6
Ta₆O₁₉^8– + H⁺ ⇌ HTa₆O₁₉^7–		16.35
HTa₆O₁₉^7– + H⁺ ⇌ H₂Ta₆O₁₉^6–		14.00
1/2 Ta₂O₅(act) + 5/2 H₂O ⇌ Ta(OH)₅	~ –5.2
Ta(OH)₅(s) ⇌ Ta(OH)₅		–5.295
Ta₂O₅(s) + 5 H₂O ⇌ 2 Ta(OH)₅		–20.00

(^a) The number of significant figures are retained to minimise propagation of round-off errors; they should not be taken to indicate the relative uncertainty of the values, which is always at least one order of magnitude less than indicated.

Tellurium(-II)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Filella and May, 2019^a^[127]
Te^2‒ + H⁺ ⇌ HTe^‒	11.81
HTe^‒ + H⁺ ⇌ H₂Te	2.476

(^a) The number of significant figures are retained to minimise propagation of round-off errors; they should not be taken to indicate the relative uncertainty of the values, which is always at least one order of magnitude less than indicated.

Tellurium(IV)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[128]	Filella and May, 2019^a^[127]
TeO₃^2‒ + H⁺ ⇌ HTeO₃^‒		9.928
HTeO₃^‒ + H⁺ ⇌ H₂TeO₃		6.445
H₂TeO₃ ⇌ HTeO₃^‒ + H⁺	‒2.68
H₂TeO₃ ⇌ TeO₃^2‒ + 2 H⁺	‒12.5
H₂TeO₃ + H⁺ ⇌ Te(OH)₃⁺	3.13	2.415
TeO₂(s) + H₂O ⇌ H₂TeO₃		‒4.709

(^a) The number of significant figures are retained to minimise propagation of round-off errors; they should not be taken to indicate the relative uncertainty of the values, which is always at least one order of magnitude less than indicated.

Tellurium(VI)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[128]	Filella and May, 2019^a^[127]
TeO₂(OH)₄^2‒ + H⁺ ⇌ TeO(OH)₅^‒		10.83
TeO(OH)₅^‒ + H⁺ ⇌ Te(OH)₆	7.68	7.696
TeO₂(OH)₄^2‒ + 2 H⁺ ⇌ Te(OH)₆	18.68
TeO₃(OH)₃^3‒ + 3 H⁺ ⇌ Te(OH)₆	34.3
2 Te(OH)₆ ⇌ Te₂O(OH)₁₁^‒ + H⁺		‒6.929

(^a) The number of significant figures are retained to minimise propagation of round-off errors; they should not be taken to indicate the relative uncertainty of the values, which is always at least one order of magnitude less than indicated.

Terbium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[28]	Brown and Ekberg, 2016^[129]
Tb³⁺ + H₂O ⇌ TbOH²⁺ + H⁺	−7.9	−7.60 ± 0.09
2 Tb³⁺ + 2 H₂O ⇌ Tb₂(OH)₂⁴⁺ + 2 H⁺		−13.9 ± 0.2
3 Tb³⁺ + 5 H₂O ⇌ Tb₃(OH)₅⁴⁺ + 5 H⁺		−31.7 ± 0.3
Tb(OH)₃(s) + 3 H⁺ ⇌ Tb³⁺ + 3 H₂O	16.5	16.33 ± 0.30

Thallium(I)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[130]	Brown and Ekberg, 2016^[131]
Tl⁺ + H₂O ⇌ TlOH + H⁺	–13.21
Tl⁺ + OH^– ⇌ TlOH		0.64 ± 0.05
Tl⁺ + 2 OH^– ⇌ Tl(OH)₂^–		–0.7 ± 0.7
⁠1/2⁠ Tl₂O(s) + H⁺ ⇌ Tl⁺ + ⁠1/2⁠ H₂O		13.55 ± 0.20

(^a) The number of significant figures are retained to minimise propagation of round-off errors; they should not be taken to indicate the relative uncertainty of the values, which is always at least one order of magnitude less than indicated.

Thallium(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[130]	Brown and Ekberg, 2016^[131]
Tl³⁺ + H₂O ⇌ TlOH²⁺ + H⁺	–0.62	–0.22 ± 0.19
Tl³⁺ + 2 H₂O ⇌ Tl(OH)₂⁺ + 2 H⁺	–1.57
Tl³⁺ + 3 H₂O ⇌ Tl(OH)₃ + 3 H⁺	–3.3
Tl³⁺ + 4 H₂O ⇌ Tl(OH)₄^– + 4 H⁺	–15.0
⁠1/2⁠ Tl₂O₃(s) + 3 H⁺ ⇌ Tl³⁺ + ⁠3/2⁠ H₂O	–3.90	–3.90 ± 0.10

(^a) The number of significant figures are retained to minimise propagation of round-off errors; they should not be taken to indicate the relative uncertainty of the values, which is always at least one order of magnitude less than indicated.

Thorium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[132]	Rand et al., 2008^[133]	Thoenen et al, 014^[134]	Brown and Ekberg, 2016^[135]
Th⁴⁺ + H₂O ⇌ ThOH³⁺ + H⁺	–3.20	–2.5 ± 0.5	–2.5 ± 0.5	–2.5 ± 0.5
Th⁴⁺ + 2 H₂O ⇌ Th(OH)₂²⁺ + 2 H⁺	–6.93	–6.2 ± 0.5	–6.2 ± 0.5	–6.2 ± 0.5
Th⁴⁺ + 3 H₂O ⇌ Th(OH)₃⁺ + 3 H⁺	< –11.7
Th⁴⁺ + 4 H₂O ⇌ Th(OH)₄ + 4 H⁺	–15.9	–17.4 ± 0.7	–17.4 ± 0.7	–17.4 ± 0.7
2Th⁴⁺ + 2 H₂O ⇌ Th₂(OH)₂⁶⁺ + 2 H⁺	–6.14	–5.9 ± 0.5	–5.9 ± 0.5	–5.9 ± 0.5
2Th⁴⁺ + 3 H₂O ⇌ Th₂(OH)₃⁵⁺ + 3 H⁺		–6.8 ± 0.2	–6.8 ± 0.2	–6.8 ± 0.2
4Th⁴⁺ + 8 H₂O ⇌ Th₄(OH)₈⁸⁺ + 8 H⁺	–21.1	–20.4 ± 0.4	–20.4 ± 0.4	–20.4 ± 0.4
4Th⁴⁺ + 12 H₂O ⇌ Th₄(OH)₁₂⁴⁺ + 12 H⁺		–26.6 ± 0.2	–26.6 ± 0.2	–26.6 ± 0.2
6Th⁴⁺ + 15 H₂O(l) ⇌ Th₆(OH)₁₅⁹⁺ + 15 H⁺	–36.76	–36.8 ± 1.5	–36.8 ± 1.5	–36.8 ± 1.5
6Th⁴⁺ + 14 H₂O(l) ⇌ Th₆(OH)₁₄¹⁰⁺ + 14 H⁺		–36.8 ± 1.2	–36.8 ± 1.2	–36.8 ± 1.2
ThO₂(c) + 4 H⁺ ⇌ Th⁴⁺ + 2 H₂O	6.3
ThO₂(am) + 4 H⁺ ⇌ Th⁴⁺ + 2 H₂O				8.8 ± 1.0
ThO₂(am,hyd,fresh) + 4 H⁺ ⇌ Th⁴⁺ + 2 H₂O			9.3 ± 0.9
ThO₂(am,hyd,aged) + 4 H⁺ ⇌ Th⁴⁺ + 2 H₂O			8.5 ± 0.9
Th⁴⁺ + 4 OH^- ⇌ ThO₂(am,hyd,fresh) + 2 H₂O		46.7 ± 0.9
Th⁴⁺ + 4 OH^- ⇌ ThO₂(am,hyd,aged) + 2 H₂O		47.5 ± 0.9

Thulium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[28]	Brown and Ekberg, 2016^[136]
Tm³⁺ + H₂O ⇌ TmOH²⁺ + H⁺	−7.7	−7.34 ± 0.09
2 Tm³⁺ + 2 H₂O ⇌ Tm₂(OH)₂⁴⁺ + 2 H⁺		−13.2 ± 0.2
3 Tm³⁺ + 5 H₂O ⇌ Tm₃(OH)₅⁴⁺ + 5 H⁺		−30.5 ± 0.3
Tm(OH)₃(s) + 3 H⁺ ⇌ Tm³⁺ + 3 H₂O	15.0	15.56 ± 0.40

Tin(II)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Feitknecht, 1963^[71]	Baes and Mesmer, 1976^[137]	Hummel et al., 2002^[45]	NIST46^[4]	Cigala et al, 2012^[138]	Gamsjäger et al, 2012^[139]	Brown and Ekberg, 2016^[140]
Sn²⁺ + H₂O ⇌ SnOH⁺ + H⁺		–3.40	–3.8 ± 0.2	–3.4	–3.52 ± 0.05	–3.53 ± 0.40	–3.53 ± 0.40
Sn²⁺ + 2 H₂O ⇌ Sn(OH)₂ + 2 H⁺		–7.06	–7.7 ± 0.2	–7.1	–6.26 ± 0.06	–7.68 ± 0.40	–7.68 ± 0.40
Sn²⁺ + 3 H₂O ⇌ Sn(OH)₃^– + 3 H⁺		–16.61	–17.5 ± 0.2	–16.6	–16.97 ± 0.17	–17.00 ± 0.60	–17.56 ± 0.40
2 Sn²⁺ + 2 H₂O ⇌ Sn₂(OH)₂²⁺ + 2 H⁺		–4.77		–4.8	–4.79 ± 0.05
3 Sn²⁺ + 4 H₂O ⇌ Sn₃(OH)₄²⁺ + 4 H⁺		–6.88	–5.6 ± 1.6	–6.88	–5.88 ± 0.05	–5.60 ± 0.47	−5.60 ± 0.47
Sn(OH)₂(s) ⇌ Sn²⁺ + 2 OH^–				–25.8	–26.28 ± 0.08
SnO(s) + 2 H⁺ ⇌ Sn²⁺ + H₂O		1.76	2.5± 0.5				1.60 ± 0.15
SnO(s) + H₂O ⇌ Sn²⁺ + 2 OH^–	–26.2
SnO(s) + H₂O ⇌ Sn(OH)₂	–5.3
SnO(s) + 2 H₂O ⇌ Sn(OH)₃^– + H⁺	–0.9

Tin(IV)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Hummel et al., 2002^[45]	Gamsjäger et al, 2012^[139]	Brown and Ekberg, 2016^[140]
Sn⁴⁺ + 4 H₂O ⇌ Sn(OH)₄ + 4 H⁺			7.53 ± 0.12
Sn⁴⁺ + 5 H₂O ⇌ Sn(OH)₅^– + 5 H⁺			–1.07 ± 0.42
Sn⁴⁺ + 6 H₂O ⇌ Sn(OH)₆^2– + 6 H⁺			–1.07 ± 0.42
Sn(OH)₄ + H₂O ⇌ Sn(OH)₅^– + H⁺	–8.0 ± 0.3	–8.60 ± 0.40
Sn(OH)₄ + 2 H₂O ⇌ Sn(OH)₆^2– + 2 H⁺	–18.4 ± 0.3	–18.67 ± 0.30
SnO₂(cr) + 2 H₂O ⇌ Sn(OH)₄	–8.0 ± 0.2	–8.06 ± 0.11
SnO₂(am) + 2 H₂O ⇌ Sn(OH)₄	–7.3 ± 0.3	–7.22 ± 0.08
SnO₂(s) + 4 H⁺ ⇌ Sn⁴⁺ + 2 H₂O			–15.59 ± 0.04

Tungsten

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	NIST46^[4]
WO₄^2– + H⁺ ⇌ HWO₄^–	3.6
WO₄^2– + 2 H⁺ ⇌ H₂WO₄	5.8
6 WO₄^2– + 7 H⁺ ⇌ HW₆O₂₁^5– + 3 H₂O	63.83

Titanium(III)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Perrin et al., 1969^[141]	Baes and Mesmer, 1976^[142]	Brown and Ekberg, 2016^[143]
Ti³⁺ + H₂O ⇌ TiOH²⁺ + H⁺	–1.29	–2.2	–1.65 ± 0.11
2 Ti³⁺ + 2 H₂O ⇌ Ti₂(OH)₂⁴⁺ + 2 H⁺		–3.6	–2.64 ± 0.10

Titanium(IV)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[142]	Brown and Ekberg, 2016^[143]
Ti(OH)₂²⁺ + H₂O ⇌ Ti(OH)³⁺ + H⁺	⩽–2.3
Ti(OH)₂²⁺ + 2 H₂O ⇌ Ti(OH)₄ + 2 H⁺	–4.8
TiO²⁺ + H₂O ⇌ TiOOH⁺ + H⁺		–2.48 ± 0.10
TiO²⁺ + 2 H₂O ⇌ TiO(OH)₂ + 2 H⁺		–5.49 ± 0.14
TiO²⁺ + 3 H₂O ⇌ TiO(OH)₃^– + 3 H⁺		–17.4 ± 0.5
TiO(OH)₂ + H₂O ⇌ TiO(OH)₃^– + H⁺		–11.9 ±0.5
TiO₂(c) +2 H₂O ⇌ Ti(OH)₄	~ –4.8
TiO₂(s) + H⁺ ⇌ TiOOH⁺		–6.06 ± 0.30
TiO₂(s) + H₂O ⇌ TiO(OH)₂		–9.02 ± 0.02
TiO₂ x H₂O ⇌ Ti(OH)₂²⁺[OH^–]
TiO₂(s) + 4 H⁺ ⇌ Ti⁴⁺ + 2 H₂O		–3.56 ± 0.10

Uranium(IV)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[144]	Thoenen et al., 2014^[145]	Brown and Ekberg, 2016^[146]	Grenthe et al., 2020^[6]
U⁴⁺ + H₂O ⇌ UOH³⁺ + H⁺	–0.65	– 0.54 ± 0.06	–0.58 ± 0.08	– 0.54 ± 0.06
U⁴⁺ + 2 H₂O ⇌ U(OH)₂²⁺ + 2 H⁺	(–2.6)	–1.1 ± 1.0	–1.4 ± 0.2	–1.9 ± 0.2
U⁴⁺ + 3 H₂O ⇌ U(OH)₃⁺ + 3 H⁺	(–5.8)	–4.7 ± 1.0	–5.1 ± 0.3	–5.2 ± 0.4
U⁴⁺ + 4 H₂O ⇌ U(OH)₄ + 4 H⁺	(–10.3)	–10.0 ± 1.4	–10.4 ± 0.5	–10.0 ± 1.4
U⁴⁺ + 5 H₂O ⇌ U(OH)₅^- + 5 H⁺	–16.0
UO₂(am, hyd) + 4 H⁺ ⇌ U⁴⁺ + 2 H₂O		1.5 ± 1.0
UO₂(am,hyd) + 2 H₂O ⇌ U⁴⁺ + 4 OH^–			–54.500 ± 1.000	–54.500 ± 1.000
UO₂(c) + 4 H⁺ ⇌ U⁴⁺ + 2 H₂O	–1.8
UO₂(c) + 2 H₂O ⇌ U⁴⁺ + 4 OH^–				–60.860 ± 1.000

Uranium(VI)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[147]	Grenthe et al., 1992^[148]	NIST46^[4]	Brown and Ekberg, 2016^[149]	Grenthe et al., 2020^[6]
UO₂²⁺ + H₂O ⇌ UO₂(OH)⁺ + H⁺	–5.8	–5.2 ± 0.3	–5.9 ± 0.1	–5.13 ± 0.04	–5.2₅ ± 0.2₄
UO₂²⁺ + 2 H₂O ⇌ UO₂(OH)₂ + 2 H⁺		≤-10.3		–12.1₅ ± 0.2₀	–12.15 ± 0.07
UO₂²⁺ + 3 H₂O ⇌ UO₂(OH)₃^– + 3 H⁺		–19.2 ± 0.4		–20.2₅ ± 0.4₂	–20.2₅ ± 0.4₂
UO₂²⁺ + 4 H₂O ⇌ UO₂(OH)₄^2– + 4 H⁺		–33 ± 2		–32.4₀ ± 0.6₈	–32.4₀ ± 0.6₈
2 UO₂²⁺ + 2 H₂O ⇌ (UO₂)₂(OH)₂²⁺ + 2 H⁺	–5.62	–5.62 ± 0.04	–5.58 ± 0.04	–5.68 ± 0.05	–5.62 ± 0.08
3 UO₂²⁺ + 5 H₂O ⇌ (UO₂)₃(OH)₅⁺ + 5 H+	–15.63	–15.5₅ ± 0.1₂	–15.6	–15.7₅ ± 0.1₂	–15.5₅ ± 0.1₂
3 UO₂²⁺ + 4 H₂O ⇌ (UO₂)₃(OH)₄²⁺ + 4 H⁺	(–11.75)	–11.9 ± 0.3		–11.78 ± 0.05	–11.9 ± 0.3
3 UO₂²⁺ + 7 H₂O ⇌ (UO₂)₃(OH)₇^– + 7 H⁺		–31 ± 2.0		–32.2 ± 0.8	–32.2 ± 0.8
4 UO₂²⁺ + 7 H₂O ⇌ (UO₂)₄(OH)₇+ + 7 H⁺		–21.9 ± 1.0		–22.1 ± 0.2	–21.9 ± 1.0
2 UO₂²⁺ + H₂O ⇌ (UO₂)₂(OH)³⁺ + H⁺		–2.7 ± 1.0			–2.7 ± 1.0
UO₂(OH)₂(s) + 2H⁺ ⇌ UO₂²⁺ + 2 H₂O	5.6		6.0	4.81 ± 0.20
UO₃·2H₂O(cr) + 2H⁺ ⇌ UO₂²⁺ + 3 H₂O					5.350 ± 0.130

Vanadium(IV)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Brown and Ekberg, 2016^[79]
VO²⁺ + H₂O ⇌ VO(OH)⁺ + H⁺	–5.30 ± 0.13
2 VO²⁺ + 2 H₂O ⇌ (VO)₂(OH)₂²⁺ + 2 H⁺	–6.71 ± 0.10

Vanadium(V)

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[150]	Brown and Ekberg, 2016^[151]
VO₂⁺ + 2 H₂O ⇌ VO(OH₎₃ + H⁺	–3.3
VO₂⁺ + 2 H₂O ⇌ VO₂(OH)₂^– + 2 H⁺	–7.3	–7.18 ± 0.12
10 VO₂⁺ + 8 H₂O ⇌ V₁₀O₂₆(OH)₂^4– + 14 H⁺	–10.7
VO₂(OH)₂^– ⇌ VO₃(OH)^2– + H⁺	–8.55
2 VO₂(OH)₂^– ⇌ V₂O₆(OH)₂^3– + H⁺ + H₂O	–6.53
VO₃(OH)^2– ⇌ VO₄^3– + H⁺	–14.26
2 VO₃(OH)^2– ⇌ V₂O₇^4– + H₂O	0.56
3 VO₃(OH)^2– + 3 H⁺⇌ V₃O₉^3– + 3 H₂O	31.81
V₁₀O₂₆(OH)₂^4– ⇌ V₁₀O₂₇(OH)^5– + 3 H⁺	–3.6
V₁₀O₂₇(OH)^5– ⇌ V₁₀O₂₈^6– + H⁺	–6.15
VO₂⁺ + H₂O ⇌ VO₂OH + H⁺		–3.25 ± 0.1
VO₂⁺ + 3 H₂O ⇌ VO₂(OH)₃^2- + 3 H⁺		–15.74 ± 0.19
VO₂⁺ + 4 H₂O ⇌ VO₂(OH)₄^3- + 4 H⁺		–30.03 ± 0.24
2 VO₂⁺ + 4 H₂O ⇌ (VO₂)₂(OH)₄^2- + 4 H⁺		–11.66 ± 0.53
2 VO₂⁺ + 5 H₂O ⇌ (VO₂)₂(OH)₅^3- + 5 H⁺		–20.91 ± 0.22
2 VO₂⁺ + 6 H₂O ⇌ (VO₂)₂(OH)₆^4- + 6 H⁺		–32.43 ± 0.30
4 VO₂⁺ + 8 H₂O ⇌ (VO₂)₄(OH)8^4- + 8 H⁺		–20.78 ± 0.33
4 VO₂⁺ + 9 H₂O ⇌ (VO₂)₄(OH)₉^5- + 9 H⁺		–31.85 ± 0.26
4 VO₂⁺ + 10 H₂O ⇌ (VO₂)₄(OH)₁₀^6- + 10 H⁺		–45.85 ± 0.26
5 VO₂⁺ + 10 H₂O ⇌ (VO₂)₅(OH)₁₀^5- + 10 H⁺		–27.02 ± 0.34
10 VO₂⁺ + 14 H₂O ⇌ (VO₂)₁₀(OH)₁₄^4- + 14 H⁺		–10.5 ± 0.3
10 VO₂⁺ + 15 H₂O ⇌ (VO₂)₁₀(OH)₁₅^5- + 15 H⁺		–15.73 ± 0.33
10 VO₂⁺ + 16 H₂O ⇌ (VO₂)₁₀(OH)₁₆^6- + 16 H⁺		–23.90 ± 0.35
⁠1/2⁠ V₂O₅(c) + H⁺ ⇌ VO₂⁺ + ⁠1/2⁠ H₂O	–0.66
V₂O₅(s) + 2 H⁺ ⇌ 2 VO₂⁺ + H₂O		–0.64 ± 0.09

Ytterbium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[28]	Brown and Ekberg, 2016^[152]
Yb³⁺ + H₂O ⇌ YbOH²⁺ + H⁺	−7.7	−7.31 ± 0.18
Yb³⁺ + 2 H₂O ⇌ Yb(OH)₂⁺ + 2 H⁺	(−15.8)
Yb³⁺ + 3 H₂O ⇌ Yb(OH)₃ + 3 H⁺	(−24.1)
Yb³⁺ + 4 H₂O ⇌ Yb(OH)₄⁻ + 4 H⁺	−32.7
2 Yb³⁺ + 2 H₂O ⇌ Yb₂(OH)₂⁴⁺ + 2 H⁺		−13.76 ± 0.20
3 Yb³⁺ + 5 H₂O ⇌ Yb₃(OH)₅⁴⁺ + 5 H⁺		−30.6 ± 0.3
Yb(OH)₃(s) + 3 H⁺ ⇌ Yb³⁺ + 3 H₂O	14.7	15.35 ± 0.20

Yttrium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[46]	Brown and Ekberg, 2016^[66]
Y³⁺ + H₂O ⇌ YOH²⁺ + H⁺	–7.7	–7.77 ± 0.06
Y³⁺ + 2 H₂O ⇌ Y(OH)₂⁺ + 2 H⁺	(–16.4) [Estimation]
Y³⁺ + 3 H₂O ⇌ Y(OH)₃ + 3 H⁺	(–26.0) [Estimation]
Y³⁺ + 4 H₂O ⇌ Y(OH)₄^-+ 4 H⁺	–36.5
2 Y³⁺ + 2 H₂O ⇌ Y₂(OH)₂⁴⁺ + 2 H⁺	–14.23	–14.1 ± 0.2
3 Y³⁺ + 5 H₂O ⇌ Y₃(OH)₅⁴⁺ + 5 H⁺	–31.6	–32.7 ± 0.3
Y(OH)₃(s) + 3 H⁺ ⇌ Y³⁺ + 3 H₂O	17.5	17.32 ± 0.30

Zinc

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[153]	Powell and Brown, 2013^[154]	Brown and Ekberg, 2016^[155]
Zn²⁺ + H₂O ⇌ ZnOH⁺ + H⁺	−8.96	−8.96 ± 0.05	−8.94 ± 0.06
Zn²⁺ + 2 H₂O ⇌ Zn(OH)₂ + 2 H⁺	−16.9	–17.82 ± 0.08	−17.89 ± 0.15
Zn²⁺ + 3 H₂O ⇌ Zn(OH)₃^- + 3 H⁺	−28.4	–28.05 ± 0.05	−27.98 ± 0.10
Zn²⁺ + 4 H₂O ⇌ Zn(OH)₄^2- + 4 H⁺	−41.2	–40.41 ± 0.12	−40.35 ± 0.22
2 Zn²⁺ + H₂O ⇌ Zn₂OH³⁺ + H⁺	−9.0	–7.9 ± 0.2	−7.89 ± 0.31
2 Zn²⁺ + 6 H₂O ⇌ Zn₂(OH)₆^2- + 6 H⁺	−57.8
ZnO(s) + 2 H⁺ ⇌ Zn²⁺ + H₂O	11.14	11.12 ± 0.05	11.11 ± 0.10
ε-Zn(OH)₂(s) + 2 H⁺ ⇌ Zn²⁺ + 2 H₂O		11.38 ± 0.20	11.38± 0.20
β₁-Zn(OH)₂(s) + 2 H⁺ ⇌ Zn²⁺ + 2 H₂O		11.72 ± 0.04
β₂-Zn(OH)₂(s) + 2 H⁺ ⇌ Zn²+ + 2 H₂O		11.76 ± 0.04
γ-Zn(OH)₂(s) + 2 H⁺ ⇌ Zn²⁺ + 2 H₂O		11.70 ± 0.04
δ-Zn(OH)₂(s) + 2 H⁺ ⇌ Zn²⁺ + 2 H₂O		11.81 ± 0.04

Zirconium

Hydrolysis constants (log values) in critical compilations at infinite dilution and T = 298.15 K:


Reaction	Baes and Mesmer, 1976^[55]	Thoenen et al., 2014^[96]	Brown and Ekberg, 2016^[156]
Zr⁴⁺ + H₂O ⇌ ZrOH³⁺ + H⁺	0.32	0.32 ± 0.22	0.12 ± 0.12
Zr⁴⁺ + 2 H₂O ⇌ Zr(OH)₂²⁺ + 2 H⁺	(−1.7)*	0.98 ± 1.06*	−0.18 ± 0.17*
Zr⁴⁺ + 3 H₂O ⇌ Zr(OH)₃⁺ + 3 H⁺	(−5.1)
Zr⁴⁺ + 4 H₂O ⇌ Zr(OH)₄ + 4 H⁺	–9.7*	–2.19 ± 0.70*	−4.53 ± 0.37*
Zr⁴⁺ + 5 H₂O ⇌ Zr(OH)₅^– + 5 H⁺	–16.0
Zr⁴⁺ + 6 H₂O ⇌ Zr(OH)₆^2– + 6 H⁺		–29± 0.70	–30.5 ± 0.3
3 Zr⁴⁺ + 4 H₂O ⇌ Zr₃(OH)₄⁸⁺ + 4 H⁺	–0.6	0.4 ± 0.3	0.90 ± 0.18
3 Zr⁴⁺ + 5 H₂O ⇌ Zr₃(OH)₅⁷⁺ + 5 H⁺	3.70
3 Zr⁴⁺ + 9 H₂O ⇌ Zr₃(OH)₉³⁺ + 9 H⁺		12.19 ± 0.20	12.19 ± 0.20
4 Zr⁴⁺ + 8 H₂O ⇌ Zr₄(OH)₈⁸⁺ + 8 H⁺	6.0	6.52 ± 0.05	6.52 ± 0.05
4 Zr⁴⁺ + 15 H₂O ⇌ Zr₄(OH)₁₅⁺ + 15 H⁺		12.58± 0.24
4 Zr⁴⁺ + 16 H₂O ⇌ Zr₄(OH)₁₆ + 16 H⁺		8.39± 0.80
ZrO₂(s) + 4 H⁺ ⇌ Zr⁴⁺ + 2 H₂O	–1.9*		–5.37 ± 0.42*
ZrO₂(s, baddeleyite) + 4 H⁺ ⇌ Zr⁴⁺ + 2 H₂O		–7 ± 1.6
ZrO₂(am) + 4 H⁺ ⇌ Zr⁴⁺ + 2 H₂O		–3.24± 0.10	–2.97 ± 0.18

*Errors in compilations concerning equilibrium and/or data elaboration. Data not recommended. It is strongly suggested to refer to the original papers.

References

^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 121.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 757–797.
^ Hummel, W.; Thoenen, T. (2023). Technical Report 21-03. The PSI Chemical Thermodynamic Database 2020. Wettingen: NAGRA. pp. 252–259.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s ^t ^u ^v ^w NIST46. NIST Critically Selected Stability Constants of Metal Complexes: Version 8.0.{{cite book}}: CS1 maint: numeric names: authors list (link)
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 407–414.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l Grenthe, I.; Gaona, X.; Plyasunov, A.V.; Rao, L.; Runde, W.H.; Grambow, B.; Konings, R.J.M.; Smith, A.L.; Moore, E.E. (2020). Second Update on the Chemical Thermodynamics of Uranium, Neptunium, Plutonium, Americium and Technetium (PDF). Paris: OECD Publishing.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. p. 414.
^ ^a ^b Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 375.
^ ^a ^b ^c Lothenbach, B.; Ochs, M.; Wanner, H.; Yui, M. (1999). Thermodynamic Data for the Speciation and Solubility of Pd, Pb, Sn, Sb, Nb and Bi in Aqueous Solution. TN8400 99-011. Japan Nuclear Cycle Development Institute (JNC).
^ ^a ^b ^c Kitamura, A.; Fujiwara, K.; Doi, R.; Yoshida, Y.; Mihara, M.; Terashima, M.; Yui, M. (2010). JAEA Thermodynamic Database for Performance Assessment of Geological Disposal of High-Level Radioactive and TRU-Wastes. Report JAEA-Data/Code 2009-024. Japan Atomic Energy Agency.
^ Filella, M.; May, P.M. (2003). "Computer simulation of the low-molecular-weight inorganic species distribution of antimony(III) and antimony(V) in natural waters". Geochim. Cosmochim. Acta. 67: 4013–4031. doi:10.1016/S0016-7037(03)00095-4.
^ ^a ^b Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 370.
^ ^a ^b Nordstrom, D.K.; Archer, D. (2003). Welch, AH; Stollenwerk, KG (eds.). Arsenic thermodynamic data and environmental geochemistry. In: Arsenic in Ground Water. Amsterdam: Kluwer Academic Publishers. pp. 1‒25. doi:10.1007/0-306-47956-7_1.
^ ^a ^b Nordstrom, D.K.; Majzlan, J.; Königsberger, E. (2014). "Thermodynamic properties for As minerals & aqueous species". Reviews in Mineralogy & Geochemistry. 79: 217‒255. doi:10.2138/rmg.2014.79.4.
^ Khodakovsky, I.L.; Ryzhenko, B.N.; Naumov, G.B. (1968). "Thermodynamics of aqueous electrolyte solutions at elevated temperatures (Temperature dependence of the heat capacities of ions in aqueous solution)". Geokhimiya. 12: 1486‒ 1503, 1968.
^ ^a ^b ^c Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 103.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j Nordstrom, D.K.; Plummer, L.N.; Langmuir, D.; Busenberg, E.; May, H.M.; Jones, B.F.; Parkhurst, D.L. (1990). Melchior, D.C.; Basset, R.L. (eds.). Revised chemical equilibrium data for major water-mineral reactions and their limitations. In: Chemical Modeling of Aqueous Systems II. Washington, DC: ACS. pp. 398–446.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. New York: Wiley. pp. 213–217.
^ ^a ^b Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 419–422.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 95.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 383.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 874–884.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 111.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 301.
^ Powell, K.J.; Brown, P.L.; Byrne, R.H.; Gajda, T.; Hefter, G.; Leuz, A.-K.; Sjöberg, S.; Wanner, H. (2011). "Chemical speciation of environmentally significant metals with inorganic ligands. Part 4: The Cd²⁺ + OH^–, Cl^–, CO₃^2–, SO₄^2–, and PO₄^3– systems (IUPAC Technical Report)". Pure Appl. Chem. 83: 1163–1214. doi:10.1351/PAC-REP-10-08-09.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 730–738.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Weinheim, Germany: Wiley. pp. 195–210.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 137.
^ ^a ^b ^c ^d ^e Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 135–145.
^ ^a ^b ^c Ball, J.W.; Nordstrom, D.K. (1998). "Critical evaluation and selection of standard state thermodynamic properties for chromium metal and its aqueous ions, hydrolysis species, oxides and hydroxides". J. Chem. Eng. Data. 43: 895–918.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 220.
^ Rai, D.; Sass, B.M.; Moore, D.A. (1987). "Chromium(III) hydrolysis constants and solubility of chromium(III) hydroxide". Inorg. Chem. 26: 345–349.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 541–555.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 216.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 241.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 620–628.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 628−632.
^ ^a ^b Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 650–702.
^ Baes, C.F.; Messmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 274.
^ Plyasunova, N.V.; Wang, M.; Zhang, Y.; Muhammed, M. (1997). "Critical evaluation of thermodynamics of complex formation of metal ions in aqueous solutions II. Hydrolysis and hydroxo-complexes of Cu²⁺ at 298.15 K". Hydrometalurgy. 45: 37–51.
^ Powell, K.J.; Brown, P.L.; Byrne, R.H.; Gajda, T.; Hefter, G.; Sjöberg, S.; Wanne, H. "Chemical speciation of environmentally significant metals with inorganic ligands. Part 2: The Cu²⁺ + OH^–, Cl^–, CO₃^2–, SO₄^2–, and PO₄^3– systems". Pure Appl. Chem. 79: 895–950 – via 2007.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 415−420.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 247, 250−251 and 290−292.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 247, 250−251 and 295−297.
^ ^a ^b ^c ^d ^e ^f Hummel, W.; Berner, U.; Curti, E.; Pearson, F.J.; Thoenen, T. (2002). TECHNICAL REPORT 02-16. Nagra/ PSI Chemical Thermodynamic Data Base 01/01.
^ ^a ^b Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 137.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 284–287.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 319.
^ Smith, R.M.; Martell, A.E.; Motekaitis, R.J. (2003). NIST Critically Selected Stability Constants of Metal Complexes Database, Version 7.0, NIST Standard Reference Database 46. Gaithersburg, MD, USA: National Institute of Standards, U.S. Dept. of Commerce.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Weinheim, Germany: Wiley. pp. 797–812.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 349.
^ Wood, S.A.; Samson, I.M. (2006). "The aqueous geochemistry of gallium, germanium, indium and scandium". Ore Geol. Rev. 28 – via 57–102.
^ Filella, M.; May, P.M. (2023). "The aqueous solution chemistry of germanium under conditions of environmental and biological interest: inorganic ligands". Applied Geochemistry. 155: 105631.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. pp. 279–285.
^ ^a ^b Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 158.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 460–463.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 247, 250−251 and 293−295.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cation. New York: Wiley. p. 327.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 812–817.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 736‒739.
^ ^a ^b Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 235.
^ ^a ^b Lemire, R.J.; Berner, U.; Musikas, C.; Palmer, D.A.; Taylor, P.; Tochiyama, O. (2013). Chemical Thermodynamics of Iron, Part 1. Chemical Thermodynamics. Vol. 13a. OECD Nuclear Energy Agency (NEA).
^ Brown, P.I.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 573−585.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 585–620.
^ Baer, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 137.
^ ^a ^b Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 135–145.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 365.
^ Powell, K.J.; Brown, P.L.; Byrne, R.H.; Gajda, T.; Hefter, G.; Leuz, A.K.; Sjöberg, S.; Wanner, H. (2009). "Chemical speciation of environmentally significant metals with inorganic ligands. Part 3: The Pb²⁺ + OH^–, Cl^–, CO₃^2–, SO₄^2–, and PO₄^3– systems (IUPAC Technical Report)". Pure Appl. Chem. 81: 2425–2476. doi:10.1351/PAC-REP-09-03-05.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 135–145.
^ Cataldo, S.; Lando, G.; Milea, D.; Orecchio, S.; Pettignano, A.; Sammartano, S. (2018). ", A novel thermodynamic approach for the complexation study of toxic metal cations by a landfill leachate". New J. Chem. 42: 7640–7648. doi:10.1039/C7NJ04456A. hdl:10447/326779.
^ ^a ^b ^c Feitknecht, W.; Schindler, P. (1963). "Solubility constants of metal oxides, metal hydroxides and metal hydroxide salts in aqueous solution". Pure and Applied Chemistry. 6 (2): 125–206. doi:10.1351/pac196306020125.
^ ^a ^b ^c ^d Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 86.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Weinheim, Germany: Wiley. pp. 136–141.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 89.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Weinheim, Germany: Wiley. pp. 178–195.
^ Perrin, D.D (1969). Dissociation constants of inorganic acids and bases in aqueous solutions. International Union of Pure and Applied Chemistry. Commission on Electroanalytical Chemistry. Butterworths. p. 181.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 226.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 557−561.
^ ^a ^b ^c Brown, P.L.; Ekberg, C (2016). Hydrolysis of Metal Ions. Wiley. pp. 568–570.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cation. New York: Wiley. p. 302.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 741–755.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 312.
^ Powell, K.J.; Brown, P.L.; Byrne, R.H.; Gajda, T.; Hefter, G.; Sjöberg, S.; Wanner, H. (2005). "Chemical speciation of environmentally significant heavy metals with inorganic ligands. Part 1: the Hg²⁺– Cl⁻, OH⁻, CO₃²⁻, SO₄²⁻, and PO₄³⁻ aqueous systems (IUPAC technical report)". Pure Appl. Chem. 77: 739–80. doi:10.1515/iupac.77.0018.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 256.
^ Jolivet, J.-P. (2000). "Metal Oxide Chemistry and Synthesis". Solution to Solid State. Wiley.
^ Crea, F.; De Stefano, C.; Irto, A.; Milea, D.; Pettignano, A.; Sammartano, S. (2017). "Modeling the acid-base properties of molybdate(VI) in different ionic media, ionic strengths and temperatures, by EDH, SIT and Pitzer equations". Journal of Molecular Liquids. 229: 15–26. doi:10.1016/j.molliq.2016.12.041.
^ Neck, V.; Altmaier, M.; Rabung, T.; Lützenkirchen, J.; Fanghänel, T. (2009). "Thermodynamics of trivalent actinides and neodymium in NaCl, MgCl₂, and CaCl₂ solutions: Solubility, hydrolysis, and ternary Ca-M(III)-OH complexes". Pure Appl. Chem. 81: 1555–1568. doi:10.1351/PAC-CON-08-09-05.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. p. 380.
^ ^a ^b Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 183.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 380–384.
^ Brownº, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 384–394.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. pp. 183–184.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 394–396.
^ Baes, C.F.; Messmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 246.
^ Gamsjäger, H.; Bugajski, J.; Gajda, T.; Lemire, R.J.; Prei, W. (2005). Chemical Thermodynamics of Nickel, Chemical Thermodynamics, Volume 6. Paris: OECD.
^ ^a ^b ^c ^d ^e ^f Thoenen, T.; Hummel, W.; Berner, U.; Curti, E. (2014). The PSI/Nagra Chemical Thermodynamic Database 12/07. Villigen PSI, Switzerland: Paul Scherrer Institut. pp. 205–212.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 632–649.
^ Filella, M.; May, P.M. (2020). "The aqueous solution thermodynamics of niobium under conditions of environmental and biological interest". Applied Geochemistry. 122. doi:10.1016/j.apgeochem.2020.104729.
^ ^a ^b Galbács, Z.M.; Zsednai, Á.; Csányi, L.J. (1983). "The acidic behaviour of osmium(VIII) and osmium(VI". Transition Met. Chem. 8: 328–332. doi:10.1007/BF00618563.
^ Perrin, D.D. (1969). Dissociation constants of inorganic acids and bases in aqueous solutions. International Union of Pure and Applied Chemistry. Commission on Electroanalytical Chemistry. Butterworths. p. 186.
^ Kitamura, A.; Yui, M. (2010). "Reevaluation of thermodynamic data for hydroxide and hydrolysis species of palladium(II) using the Brønsted-Guggenheim Scatchard model". J. Nuclear Sci. Technol. 47: 760−770. doi:10.1080/18811248.2010.9711652.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 723−725.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. pp. 186–187.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 396–397.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. pp. 187–189.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 397–401.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. pp. 189–190.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 401–403.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. pp. 190–191.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 403–405.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 148–150.
^ Perrin, D.D. (1969). Dissociation constants of inorganic acids and bases in aqueous solutions. International Union of Pure and Applied Chemistry. Commission on Electroanalytical Chemistry. Butterworths. p. 191.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 263.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. p. 722.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 128.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 225–236.
^ ^a ^b ^c Olin, Å; Noläng, B.; Öhman, L.-O.; Osadchii, E; Rosén, E. (2005). Chemical Thermodynamics of Selenium. OECD Pub.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 386.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 387.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 342.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 278.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 725−730.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Weinheim, Germany: Wiley. pp. 142–147.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Weinheim, Germany: Wiley. pp. 210–213.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 252.
^ Filella, M.; May, P.M. (2019). "The aqueous solution thermodynamics of tantalum under conditions of environmental and biological interest". Applied Geochemistry. 109: 104402. doi:10.1016/j.apgeochem.2019.104402.
^ ^a ^b ^c Filella, M.; May, P.M. (2019). "The aqueous chemistry of tellurium: critically-selected equilibrium constants for the low-molecular-weight inorganic species". Environ. Chem. 16: 289–295. doi:10.1071/EN19017.
^ ^a ^b Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 395.
^ Brwon, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 247, 250−251 and 287−290.
^ ^a ^b Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 335.
^ ^a ^b Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 817–826.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 168.
^ Rand, M.; Fuger, J.; Grenthe, I.; Neck, V.; Rai, D. (2008). Chemical Thermodynamics of Thorium (PDF). OECD Publishing.
^ Thoenen, T.; Hummel, W.; Berner, U.; Curti, E. (2014). The PSI/Nagra Chemical Thermodynamic Database 12/07. Villigen: Paul Scherrer Institut PSI. pp. 259–263.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 462–498.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 247, 250−251 and 297−300.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 357.
^ Cigala, R.M.; Crea, F.; De Stefan, C.; Lando, G.; Milea, D.; Sammartano, S. (2012). "The inorganic speciation of tin(II) in aqueous solution". Geochim. Cosmochim. Acta. 87: 1–20. doi:10.1016/j.gca.2012.03.029.
^ ^a ^b Gamsjäger, H.; Gajda, T.; Sangster, J.; Saxena, S.K.; Voigt, W. (2012). Chemical Thermodynamics of Tin. Chemical Thermodynamics Volume 12. Paris: OECD.
^ ^a ^b Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 836–842.
^ Perrin, D.D. (1969). Dissociation Constants of Inorganic Acids and Bases in Aqueous Solution. International Union of Pure and Applied Chemistry. Commission on Electroanalytical Chemistry. Butterworths. p. 208.
^ ^a ^b Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 151.
^ ^a ^b Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 433–442.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 181.
^ Thoenen, T.; Hummel, W.; Berner, U.; Curti, E. (2014). The PSI/Nagra Chemical Thermodynamic Database 12/07 (PDF). Villigen: Paul Scherrer Institut PSI.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley (published 336–349).
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cation. New York: Wiley. p. 182.
^ Grenthe, I.; Fuger, J.; Konings, R.J.M.; Lemire, R.J.; Muller, A.B.; Nguyen-Trung, C.; Wanner, H. (1992). Chemical Thermodynamics of Uranium, Chemical Vol 1, (PDF). Paris: OECD Publishing.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 350–379.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 209.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 517–541.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 247, 250−251 and 300−303.
^ Baes, C.F.; Mesmer, R.E. (1976). The Hydrolysis of Cations. New York: Wiley. p. 293.
^ Powell, K.J.; Brown, P.L.; Byrne, R.H.; Gajda, T.; Hefter, G.; Leuz, A.-K.; Sjöberg, S.; Wanner, H. (2013). "Chemical speciation of environmentally significant metals with inorganic ligands. Part 5: The Zn²⁺ + OH^–, Cl^–, CO₃^2–, SO₄^2–, and PO₄^3– systems (IUPAC Technical Report)*". Pure and Applied Chemistry. 85: 2249–2311.
^ Brown, P.L.; Ekberg, C (2016). Hydrolysis of Metal Ions. Wiley. pp. 676−700.
^ Brown, P.L.; Ekberg, C. (2016). Hydrolysis of Metal Ions. Wiley. pp. 442–460.

Retrieved from "https://en.wikipedia.org/w/index.php?title=Hydrolysis_constant&oldid=1240728687"