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

244
X Group 15 compounds and complexes
This selection yields:
Δ ο
f G m (SnAs, cr, 298.15 K) = − (10.0 ± 3.2) kJ·mol–1 .
X.3.1.2
Sn 4 As 3 (cr)
Koshchenko et al. [1980KOS/PAS], [1980KOS/DEM] measured the heat capacity of
solid solutions in the system Sn-As with 57 to 60% Sn close to the composition Sn 4 As 3
in the temperature range 5.5 to 310 K. The measurement errors are similar to those for
SnAs, namely 1.5% between 5 and 40 K and 0.5% above 40 K. Two different
compositions were used with w(Sn) = 0.58 and 0.59; the difference in the heat capacity
between the two compositions was approximately 1.2%. The numerically integrated
data for the w(Sn) = 0.58 and the 0.59 compound are reported in Table X-7 and Table
X-8 respectively, and compared with appropriate fit functions in Figure X-5.
Table X-7: Thermodynamic properties of Sn 3 As 4 . Smoothed and numerically integrated
data on Sn 4 As 3 with 58% Sn. Values in parentheses have been recalculated by modified
fit functions, see Appendix A entry for [1980KOS/PAS].
T/K
ο
p,m
C /J·K –1·mol –1 HT ( ) − H(0K)/
J·mol –1
ο
S m /J·K –1·mol –1 −[( GT ( ) − G(0 K)) T −1
] /
–1
J·K
–1·mol
5.00 0.381 (0.433) 0.88 (0.541) 0.127 (0.144) − 0.049 (0.036)
10.00 4.60 (3.860) 13.3 (8.368) 2.04 (1.072) 0.71 (0.235)
15.00 15.6 (14.646) 63.7 (53.939) 6.07 (4.625) 1.82 (1.029)
20.00 27.5 (27.131) 171 (158.184) 12.2 (10.537) 3.67 (2.628)
25.00 38.5 (39.274) 336 (324.587) 19.6 (17.913) 6.12 (4.930)
30.00 49.2 (50.258) 556 (548.958) 27.5 (26.064) 9.0 (7.765)
35.00 60.0 (59.938) 828 (824.981) 35.9 (34.555) 12.2 (10.984)
40.00 69.9 (69.320) 1153 (1146.310) 44.6 (43.123) 15.8 (14.465)
45.00 79.1 (79.149) 1526 (1519.363) 53.9 (51.901) 20.0 (18.137)
50.00 88.0 (88.271) 1944 (1937.992) 62.1 (60.713) 23.3 (21.953)
60.00 105.5 (104.694) 2920 (2905.318) 79.8 (78.304) 30.5 (29.882)
70.00 117.8 (117.911) 4030 (4020.894) 97.0 (95.475) 37.7 (38.034)
80.00 128.0 (128.283) 5260 (5253.920) 113 (111.924) 45.1 (46.250)
90.00 136.2 (136.425) 6590 (6579.026) 129 (127.522) 55.778 (54.422)
100.00 143.1 (142.875) 7980 (7976.699) 144 (142.242) 64.200 (62.475)
110.00 148.0 (148.045) 9440 (9432.176) 158 (156.111) 72.182 (70.364)
120.00 152.2 (152.247) 10900 (10934.296) 171 (169.178) 80.167 (78.059)
130.00 155.6 (155.709) 12500 (12474.571) 183 (181.505) 86.846 (85.547)
(Continued on next page)
CHEMICAL THERMODYNAMICS OF TIN, ISBN 978-92-64-99206-1, © OECD 2012