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

A Discussion of selected references
363
T/K
ο
p,m
C (SnO, cr, T )/ T/K
–1
J·mol
–1·K
Table A-38 (continued)
ο
p,m
C (SnO, cr, T )/ T/K
–1
J·mol
–1·K
ο
p,m
C (SnO, cr, T )/
–1
J·mol
–1·K
150.487 33.4975 201.833 40.2179 258.568 45.7156
153.445 33.7506 206.248 40.2693 262.970 45.8173
154.618 33.8703 210.157 40.9835 267.330 46.1717
158.891 34.5569 212.739 41.4576 270.928 46.5365
163.663 35.1770 216.740 41.7885 275.995 46.7436
165.199 35.3586 218.064 41.7254 280.258 46.7909
168.878 35.9242 220.741 42.0032 284.513 47.0633
169.868 35.9050 222.758 42.2019 298.925 47.2888
174.008 36.6175 228.622 43.0354 294.190 47.4976
179.713 37.4284 232.511 43.3621 298.343 47.7294
183.489 37.7493 236.368 43.5969 302.467 48.0181
187.599 38.6028 236.556 43.6048 306.599 48.2005
191.262 38.9083 245.656 44.1805 310.707 48.3716
In this temperature range the coefficients of
a) an exponential power function
bx /
y = ax
(A.70)
ο (SnO, cr, )/J·K −1 ·mol −1 77.816( /K) [ −25.295(K/ T )]
Cp, m
T = T
and
b) the Gompertz function
y = aexp{ −exp[ b− cln( x)]}
(A.71)
o
C
p, m
(SnO, cr, T )/J·K –1·mol –1 = 85.825 exp{− exp[3.5131 – 0.71245 ln(T/K)]} were
fitted to the data of Table A-38. Approaches a) and b) led to C o p, m
(SnO, cr) =
47.989 J·K –1·mol –1 and C
o p, m
(SnO, cr) = 48.093 J·K –1·mol –1 , respectively. A better
agreement with Kostryukov et al.’s result was obtained from the linear regression of the
data between 262.97 ≤ T/K ≤ 310.71, C (SnO, cr) = (47.756 ± 0.076) J·K –1·mol –1 .
o
p, m
The entropy was calculated a) by nonlinear regression of C o / p, m
T vs. T,
o
refitting the coefficients of ( ( Cp, m
/ T )/J·K –2·mol –1 = 78.528 (T/K) [− 25.519(K/T) − 1] ) and
o
integrating with respect to T and b) by integrating the Gompertz function of C
p, m
with
respect to ln (T/K), resulting in
ο
a) S
m
(SnO, cr, 298.15 K) = (57.180 ± 0.223) J·K –1·mol –1 and
ο
b) S
m
(SnO, cr, 298.15 K) = (57.105 ± 0.260) J·K –1·mol –1 .
CHEMICAL THERMODYNAMICS OF TIN, ISBN 978-92-64-99206-1, © OECD 2012