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

196
VIII Group 17 (halogen) compounds and complexes
Zmbov et al. [1968ZMB/HAS] examined the gaseous species above liquid
SnF 2 in the range 520 to 623 K by mass spectrometry. The third law results in
Table VIII-16 involved a correction [1991GUR/VEY] for the formation of dimer
molecules Sn 2 F 4 (g) of 20% of the total pressure.
here, is
The final weighted average value for the enthalpy of sublimation, selected
Δ H (SnF 2 , cr, 298.15 K) = (166 ± 2) kJ·mol –1
sub
ο
m
from the preferred third-law values.
From the selected enthalpies of formation and sublimation of SnF 2 (cr) here
given, the quantity
Δ H (SnF 2 , g, 298.15 K) = – (535 ± 3) kJ·mol –1
f
ο
m
is adopted as selected value.
The selected heat-capacity data for gaseous SnF 2 [1991GUR/VEY] may be
generated by the equation
ο 600K
p,m 100K
[ C ] (SnF 2 , g, T )/J·K –1·mol –1 = 29.68 + 0.09146 T/K − 8.175 × 10 –5 (T/K) 2 .
which yields:
Standard error of estimate is 0.3 J·K –1·mol –1 .
Other selected data are:
ο
–1
C p,m (SnF 2 , g, 298.15 K) = (49.7 ± 0.1) J·K
–1·mol
ο
S m (SnF 2 , g, 298.15 K) = (282.1 ± 0.1) J·K –1·mol –1 ,
Δ G (SnF 2 , g, 298.15 K) = − (543.4 ± 3.0) kJ·mol –1 .
f
ο
m
VIII.4.1.2 SnF 4 (g)
Thermodynamic properties given by [1991GUR/VEY] are semi-empirical estimates and
there are no experimental data as a basis for evaluation.
VIII.4.2 Gaseous chlorides
VIII.4.2.1 SnCl 2 (g)
Ideal gas properties of SnCl 2 were calculated by [1991GUR/VEY], [1963BRE/SOM]
and [1964NAG2] from spectroscopic and structural data. The data were those of
[1938ASU/KAR], [1941LIS/SUT], [1958AKI/SPI], [1964DES/PAN],
[1966NAE/PAL], [1969HAS/HAU], [1969PER], [1970AND/FRE], [1970BEA/PER],
[1971HUB/OZI] and [1976TEV/NAK]. Gurvich and Veyts [1991GUR/VEY]
CHEMICAL THERMODYNAMICS OF TIN, ISBN 978-92-64-99206-1, © OECD 2012