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Heat capacity and thermodynamic properties of NaTi3(SO3)2 from 10 to 330 K
M-1090(N) J. Chem.
Thermodynamics
1980, 12, 301-302
Notes Heat capacity and thermodynamic from 10 to 330 K
properties
of NaT13(SO&
G. COFFY,” T. MATSUO,b S. SUNNER, and A. TRANQUARDC ThermochemistryLaboratory, ChemicalCenter, University of Lund, S-22007 Lund, Sweden (Received19 July 1979)
Sodium trithallium(1) sulfite NaTl,(SO,), has an a-phase stable at room temperature.“’ It was prepared by reaction between thallous nitrate and sodium sulfite and the stoichiometry checked by titration of Tl(1) and Na.(‘) Infrared and Raman spectra strongly suggested an ordered structure.(3) In an attempt to confirm that result a study of the structure by X-ray diffraction was undertaken,‘4’ showing that the a-phase is trigonal with PJml space group and parameters a = 0.5723 nm, c=0.7216nm,p=6.41gcm-3,andZ=1. This note reports a determination of the heat capacity of the substance between 10 and 330 K using an adiabatic calorimeter cryostat previously described.@’ A goldplated copper calorimeter with an internal volume of about 10 cm3 was used. Temperatures were measured with a Mince S 1059 miniature platinum resistance thermometer, located in the central well of the calorimeter. The calorimeter was loaded with sample (m = 30.3097 g), evacuated, and helium gas added to 7.8 kPa at 298 K to provide thermal contact between sample and calorimeter. It was then sealed, placed in the cryostat, and cooled. The heat capacity of the empty calorimeter was determined in a separate series of measurements. Small corrections were applied for ‘zero drift’ of the calorimeter temperature and for difference in the amounts of gold. helium gas, and Apiezon T grease. In agreement with the results recently reported,‘3,4’ no phase transition was found between 10 and 330 K. The values of C,, S”(T), and {H”(T)-H”(O)}/T are given at selected temperatures in table 1. They were obtained by least-squares fitting of the experimental heat capacities to polynomials. At the lowest temperatures the heat capacities were smoothed with the aid of a plot of C,/T against TZ and the functions were evaluated by extrapolation of this plot beyond 10 K. a On leave from Laboratoire de physico-chimie minirale 3, Universite Claude Bernard Lyon I, Villeurbanne, France. * On leave from Department of Chemistry, Osaka University, Osaka, Japan. c Laboratoire de physico-chimie mintrale 3, Universite Claude Barnard Lyon I, Villeurbanne. France. 0021-9614/80/030301+02
$01.00/O
0 1980 Academic Press Inc. (London) Ltd
NOTES
302
TABLE 1. Thermodynamic functions of NaTl,(SO,), T it
CP
J K-t mol-’
10 15 20 25 30 35 40 45 50 60 70 80 90 100 110 120 130 140 150 160
11.340 24.752 38.100 50.85 62.78 73.87 84.19 93.84 102.89 119.16 132.85 144.18 153.78 162.10 169.45 176.06 182.06 187.58 192.70 197.50
S”(T)-S”(O)
J K-t mol-’ 3.441 10.563 19.522 29.407 39.745 50.26 60.81 71.29 81.65 101.88 121.29 139.79 157.34 173.98 189.78 204.82 219.15 232.85 245.96 258.56
{H”(T)-H”(O)}/T
J K-’ mol-’ 2.580 7.721 13.660 19.835 26.010 32.064 37.942 43.623 49.103 59.46 68.97 77.69 85.62 92.86 99.50 105.61 111.26 116.52 121.43 126.03
T
it
CP
S”(T)-S”(0)
J K-t mol-’
J K-r mol-’
170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330
270.57 282.36 293.60 309.82 315.07 325.32 335.29 345.00 354.47 363.72 372.75 381.58 390.21 398.66 406.91 415.00 422.93
130.37 134.47 138.37 143.86 145.62 149.02 152.29 155.46 158.52 161.49 164.37 167.17 169.68 172.53 175.08 177.57 180.00
273.15 298.15
242.15 249.92
375.56 397.11
165.26 172.05
REFERENCES 1. 2. 3. 4. 5.
(H”(T)-H”(O)}/T
J K-’ mol-t 202.02 206.33 210.49 216.52 218.50 222.41 226.29 230.12 233.89 237.56 241.08 244.41 247.53 250.45 253.25 256.08 259.28
Oddon, Y.; Coffy, G.; Tranquard, A. Bull. Sot. Chim. 1975, 7-8, 1481. Oddon, Y.; Caranoni, C.; Tranquard, A. CR. Acad. Sci. 1973, 276, C, 61. Vignalou, J. R.; Tranquard, A.; Cotui, M. Spectrochimica Acta 1977, 33A, 767. Oddon, Y. ; Pepe, G. ; Tranquard, A. J. Chem. Research 1977, 138. Arvidsson, K.; Falk, B.; Sunner, S. Chemica Scripta 1976, 10, 193.
Thermodynamics
1980, 12, 301-302
Notes Heat capacity and thermodynamic from 10 to 330 K
properties
of NaT13(SO&
G. COFFY,” T. MATSUO,b S. SUNNER, and A. TRANQUARDC ThermochemistryLaboratory, ChemicalCenter, University of Lund, S-22007 Lund, Sweden (Received19 July 1979)
Sodium trithallium(1) sulfite NaTl,(SO,), has an a-phase stable at room temperature.“’ It was prepared by reaction between thallous nitrate and sodium sulfite and the stoichiometry checked by titration of Tl(1) and Na.(‘) Infrared and Raman spectra strongly suggested an ordered structure.(3) In an attempt to confirm that result a study of the structure by X-ray diffraction was undertaken,‘4’ showing that the a-phase is trigonal with PJml space group and parameters a = 0.5723 nm, c=0.7216nm,p=6.41gcm-3,andZ=1. This note reports a determination of the heat capacity of the substance between 10 and 330 K using an adiabatic calorimeter cryostat previously described.@’ A goldplated copper calorimeter with an internal volume of about 10 cm3 was used. Temperatures were measured with a Mince S 1059 miniature platinum resistance thermometer, located in the central well of the calorimeter. The calorimeter was loaded with sample (m = 30.3097 g), evacuated, and helium gas added to 7.8 kPa at 298 K to provide thermal contact between sample and calorimeter. It was then sealed, placed in the cryostat, and cooled. The heat capacity of the empty calorimeter was determined in a separate series of measurements. Small corrections were applied for ‘zero drift’ of the calorimeter temperature and for difference in the amounts of gold. helium gas, and Apiezon T grease. In agreement with the results recently reported,‘3,4’ no phase transition was found between 10 and 330 K. The values of C,, S”(T), and {H”(T)-H”(O)}/T are given at selected temperatures in table 1. They were obtained by least-squares fitting of the experimental heat capacities to polynomials. At the lowest temperatures the heat capacities were smoothed with the aid of a plot of C,/T against TZ and the functions were evaluated by extrapolation of this plot beyond 10 K. a On leave from Laboratoire de physico-chimie minirale 3, Universite Claude Bernard Lyon I, Villeurbanne, France. * On leave from Department of Chemistry, Osaka University, Osaka, Japan. c Laboratoire de physico-chimie mintrale 3, Universite Claude Barnard Lyon I, Villeurbanne. France. 0021-9614/80/030301+02
$01.00/O
0 1980 Academic Press Inc. (London) Ltd
NOTES
302
TABLE 1. Thermodynamic functions of NaTl,(SO,), T it
CP
J K-t mol-’
10 15 20 25 30 35 40 45 50 60 70 80 90 100 110 120 130 140 150 160
11.340 24.752 38.100 50.85 62.78 73.87 84.19 93.84 102.89 119.16 132.85 144.18 153.78 162.10 169.45 176.06 182.06 187.58 192.70 197.50
S”(T)-S”(O)
J K-t mol-’ 3.441 10.563 19.522 29.407 39.745 50.26 60.81 71.29 81.65 101.88 121.29 139.79 157.34 173.98 189.78 204.82 219.15 232.85 245.96 258.56
{H”(T)-H”(O)}/T
J K-’ mol-’ 2.580 7.721 13.660 19.835 26.010 32.064 37.942 43.623 49.103 59.46 68.97 77.69 85.62 92.86 99.50 105.61 111.26 116.52 121.43 126.03
T
it
CP
S”(T)-S”(0)
J K-t mol-’
J K-r mol-’
170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330
270.57 282.36 293.60 309.82 315.07 325.32 335.29 345.00 354.47 363.72 372.75 381.58 390.21 398.66 406.91 415.00 422.93
130.37 134.47 138.37 143.86 145.62 149.02 152.29 155.46 158.52 161.49 164.37 167.17 169.68 172.53 175.08 177.57 180.00
273.15 298.15
242.15 249.92
375.56 397.11
165.26 172.05
REFERENCES 1. 2. 3. 4. 5.
(H”(T)-H”(O)}/T
J K-’ mol-t 202.02 206.33 210.49 216.52 218.50 222.41 226.29 230.12 233.89 237.56 241.08 244.41 247.53 250.45 253.25 256.08 259.28
Oddon, Y.; Coffy, G.; Tranquard, A. Bull. Sot. Chim. 1975, 7-8, 1481. Oddon, Y.; Caranoni, C.; Tranquard, A. CR. Acad. Sci. 1973, 276, C, 61. Vignalou, J. R.; Tranquard, A.; Cotui, M. Spectrochimica Acta 1977, 33A, 767. Oddon, Y. ; Pepe, G. ; Tranquard, A. J. Chem. Research 1977, 138. Arvidsson, K.; Falk, B.; Sunner, S. Chemica Scripta 1976, 10, 193.