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

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VIII Group 17 (halogen) compounds and complexes
This selection yields:
Δ G (SnBr 2 , g, 298.15 K) = − (155.8 ± 4.3) kJ·mol –1 .
f
ο
m
From mass spectrometric measurements on the vapour above liquid tin(II)
bromide evidence was found for the existence of dimers Sn 2 Br 4 [1969KAR2]. This
finding was corroborated later in more detailed measurements [1991HIL/MIL2],
[1992BRU/WAL2]. Partial pressures of monomer and dimer in the vapour phase were
determined by [1991HIL/MIL2] between 423 and 573 K. Their data, when extrapolated
to 298 K, indicate that the mole fraction of dimers in the gas phase is approximately
0.01.
VIII.4.3.2 SnBr 4 (g)
Ideal gas properties of gaseous SnBr 4 were calculated by [1962ANA] and
[1991GUR/VEY] from spectroscopic and structural data. The data were those of
[1941LIS/SUT], [1973DER/KOV], [1971CLA/RIP], [1972CLA/RIP],
[1972CLA/RIP2], [1954DEL/FRA], [1977KON/MUL], [1971CLA/WIL],
[1979CRE/SIN], [1976KON/MUL] and [1963MOS]. Gurvich and Veyts
[1991GUR/VEY] re-evaluated the data and performed the caculations using the rigid
rotator-harmonic oscillator approximation. Reported data appear in Table VIII-26.
Table VIII-26: Ideal gas properties of SnBr 4 from compilations/evaluations (C/E) and
original article (A).
ο
p,m
S m
ο
Reference
C (SnBr 4 , g, 298.15 K)/ (SnBr 4 , g, 298.15 K)/
ο
Δ fHm
(SnBr 4 , g, 298.15 K)/
–1
J·K
–1·mol
–1
J·K
–1·mol kJ·mol –1
[1962ANA] (A) 103.4 412.6 -
[1991GUR/VEY] (C/E) 103.284 (a) 413.228 (a) − 324.217 ± 4.5 (a)
[1973BAR/KNA] (C/E) 103.34 411.8 − 314.6
[1993BAR] (C/E) 103.422 412.652 − 348.109
[1999BIN/MIL] (C/E) 103.3 412.4 − 347.6
[1982WAG/EVA] (C/E) - - − 314.6
(a) Selected data.
The standard enthalpy of formation of gaseous SnBr 4 may be derived from data
for the condensed phase compound. In Section VIII.1.3.2, the value
f
ο
m
Δ H (SnBr 4 , cr, 298.15 K) = − (388.0 ± 3.0) kJ·mol –1
was selected. The enthalpy of sublimation may be deduced from vapour pressure
measurements. Table VIII-27 summarises vapour pressure data sources. The enthalpy of
sublimation was derived from these data, with the use of evaluated auxiliary data for
CHEMICAL THERMODYNAMICS OF TIN, ISBN 978-92-64-99206-1, © OECD 2012