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

264
A Discussion of selected references
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Figure A-4: E app,HCl of Sn(IV)/Sn(II) vs. c −
(Cl )tot
(experimental data of [1914FOR/BAR]
(), solid line, : E = (145.1 ± 1.8) mV).
ο
app,0
(E - (k / 2) log 10
[c Sn(IV)
/ c Sn(II)
] ) / mV
150
140
130
120
110
100
90
80
E° [Sn(IV) / Sn(II)] = (145.1 ± 1.8) mV
b = -(9.4 ± 0.7) mV·M -1
exp. data [1914FOR/BAR]
linear fit vs. c(Cl – ) tot
95% confidence limits
0 1 2 3 4 5 6
c(Cl – ) tot
/ M
Figure A-5: Correction term connecting log 10 {m Sn(IV) /m Sn(II) } and log 10 { m 4 2
Sn
/ mSn
depends on m Cl
− (: actual measurements; : (0,0) schematic calculation using
β = m /{ m 2 m –}
; dashed line: linear extrapolation of the data).
+ +
1(2)
SnCl Sn Cl
+ + }
log(1+β 1(2)·m Cl
–) - log(1+β 1(4)·m Cl
–+β 2(4)·m 2 Cl –)
0
-1
-2
-3
-4
-5
schematic calculation using
β 1(2)
= m(SnCl + ) / {m(Sn 2+ )·m(Cl – )}
log β 1(2)
= 1.34 (I = 0, 298.15 K)
β 1(4)
= m(SnCl 3+ ) / {m(Sn 4+ )·m(Cl – )}
log β 1(4)
= 3.59 (I = 5 M HClO4)
β 2(4)
= m(SnCl 2 2+ ) / {m(Sn 4+ )·m 2 (Cl – )}
log β 2(4)
= 6.24 (I = 5 M HClO4)
-6
0 1 2 3 4 5 6
m Cl
– / mol·kg –1
CHEMICAL THERMODYNAMICS OF TIN, ISBN 978-92-64-99206-1, © OECD 2012