Chemical Thermodynamics of Tin - Volume 12 - OECD Nuclear ...

VIII.3 Aqueous halide complexes
189
Vanderzee studied the complex formation processes at I = 3 M and at
four different temperatures [1952VAN]. The recalculated formation constants
(Table VIII-11) were used to derive reaction enthalpies of the Reactions ((VIII.13), q =
ο
1, 2, 3): Δ rHm(VIII.13) = (5.1 ± 2.0), (12.9 ± 2.0) and (7.2 ± 4.0) kJ·mol –1 , respectively
(see Appendix A). The heats of the Reactions ((VIII.13), q = 1, 2) show distinct ionic
strength dependence (Figure VIII-27 and Figure VIII-28). Since similar behaviour can
be expected in case of bromide for the Reactions ((VIII.13), q = 1, 2, 3), the above
reactions enthalpies cannot be recommended as selected standard values, but can be
used as estimates.
Table VIII-11: Experimental formation constants of the species SnBr
Method Ionic media t/°C log10
Sn 2+ + Br – SnBr +
Reported Recalculated (a) Accepted (b)
β
q
2 − q
q
.
Reference
Ise-Sn 0 corr ((H/K)Br) 25 1.11 0.92 0.92 ± 0.50 [1928PRY]
kin 2.03 M HClO 4 25 0.43 0.37 ± 0.50 (c) [1951DUK/PIN]
Ise-Sn 3 M (H/Na)ClO 4 0 0.63
0.64 ± 0.02 0.57 ± 0.30 [1952VAN]
25
35
45
0.73
0.76
0.79
0.73 ± 0.01
0.75 ± 0.01
0.78 ± 0.03
0.66 ± 0.30
0.68 ± 0.30
0.71 ± 0.30
Ise-Sn 1.0 M NaClO 4 25 0.74 ± 0.04 0.82 ± 0.01 0.80 ± 0.30 [1969FED/BOL]
2.0 M NaClO 4
3.0 M NaClO 4
4.0 M NaClO 4
6.0 M NaClO 4
8.0 M NaClO 4
25
25
25
25
25
0.57 ± 0.07
0.78 ± 0.02
0.85 ± 0.02
1.18 ± 0.03
1.60 ± 0.04
0.62 ± 0.01
0.77 ± 0.01
0.89 ± 0.02
1.20 ± 0.02
1.45 ± 0.14
0.58 ± 0.30
0.70 ± 0.30
0.80 ± 0.30
1.03 ± 0.40
Ise-Sn 0.5 M NaClO 4 25 1.09 ± 0.10 1.08 ± 0.40 [1975FED/BOL]
Ise-Sn 1.0 M LiClO 4 25 0.95 ± 0.06 [1976SAM/LYA]
vlt 1.0 M NaNO 3 25 0.60 ± 0.10 0.61 ± 0.13
[1981PET/MIL]
0 corr (NaBr) 25
0.95 ± 0.50 0.95 ± 0.50
Möss 3.5 M
(e)
1.34 [1984HSU/CHE]
(d)
(Na,H)(ClO 4 ,Br)
Sn 2+ + 2 Br – SnBr 2 (aq)
Ise-Sn 0 corr ((H/K)Cl) 25 1.81 1.51 1.51 ± 0.50 [1928PRY]
Ise-Sn 3 M (H/Na)ClO 4 0
25
35
45
0.95
1.14
1.19
1.27
0.90 ± 0.11
1.10 ± 0.04
1.18 ± 0.01
1.25 ± 0.09
0.77 ± 0.30
0.97 ± 0.30
1.05 ± 0.30
1.12 ± 0.30
[1952VAN]
(Continued on next page)
CHEMICAL THERMODYNAMICS OF TIN, ISBN 978-92-64-99206-1, © OECD 2012