Abstract
The effect of the water vapor pressure on the thermal dehydration of manganese(II) formate dihydrate was studied by means of isothermal gravimetry under various water vapor pressure, ranging from 4.6 to 24.4 torr.
The kinetics of dehydration was described by a two-dimensional phase-boundary model,R 2. The rate of dehydration decreased with increasing atmospheric water vapor pressure, but the Smith-Topley phenomenon was not observed for the present dehydration. The activation energy and the frequency factor for the dehydration were 110–170 kJ·mol−1 and 1010–1016 cm·s−1, respectively. These values increased with increasing water vapor pressure, and were much larger than those reported for the dehydration in vacuum.
Zusammenfassung
Mittels isothermer Gravimetrie wurde bei verschiedenen Wasserdampfdrücken zwischen 4.6 und 24.4 Torr der Einfluß von Wasserdapfdruck auf die thermische Dehydratation von Mangan(II)formiat-Dihydrat untersucht.
Die Kinetik der Dehydratation wurde mittels eines zweidimensionalen PhasengrenzmodellesR 2 beschrieben. Die Dehydratationsgeschwindigkeit sinkt mit zunehmendem atmosphärischen Wassergasdruck, jedoch wird das Smith-Topley-Phänomen für die vorliegende Dehydration nicht beobachtet. Aktivierungsenergie und Frequenzfaktor der Dehydratation betrugen 110–170 kJ/mol bzw. 1010–1016 cm/s. Diese werte steigen mit zunehmendem Wassergasdruck und sind wesentlich größer als die für die Dehydration in Vakuum beschriebenen Werte.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
M. L. Smith and B. Topley, Proc. Roy. Soc. Ser. A, 134 (1931) 224.
B. Topley and M. L. Smith, J. Chem. Soc., (1935) 321.
W. E. Garner and M. G. Tanner, J. Chem. Soc., (1930) 40.
W. E. Garner and T. S. Jennings, Proc. Roy. Soc. Ser. A, 224 (1954) 460.
D. Dollimore, T. E. Jones and P. Spooner, J. Chem. Soc. Ser. A, (1970) 2809.
D. Dollimore, G. R. Heal and J. Mason, Thermochim. Acta, 24 (1978) 307.
Y. Masuda and K. Nagagata, Thermochim. Acta, 155 (1989) 255.
Y. Masuda, K. Hirata and Y. Ito, Thermochim. Acta, 203 (1992) 289.
Y. Masuda and Y. Ito, J. Thermal Anal., 38 (1992) 1793.
Y. Masuda, K. Iwata, R. Ito and Y. Ito, J. Phys. Chem., 91 (1987) 6543.
Kgaku Binran Kisohen II, (Handbook of Chemistry), The Chemical Society of Japan, Maruzen, Tokyo, 4th edn., 1992, p. 245.
J. H. Shap, G. W. Brindley and B. N. N. Achar, J. Amer. Ceram. Soc., 49 (1966) 379.
S. F. Hulbert, J. Br. Ceram. Soc., 6 (1969) 11.
J. Sestak and G. Berggen, Thermochim. Acta, 3 (1971) 1.
K. Heide, W. Holand, H. Golker, K. Seyfarth, B. Muller and R. Sauer, Thermochim. Acta, 13 (1975) 365.
R. C. Eckhardt and T. B. Flanagan, Trans. Faraday Soc., 60 (1964) 1289.
T. A. Clarke and J. M. Thomas, J. Chem. Soc., Ser. A, (1969) 2227.
K. Osaki, Y. Nakai and T. Watanabe, J. Phys. Soc. Jpn., 19 (1964) 713.
Y. Masuda and K. Nagagata, Thermochim. Acta, 161 (1990) 55.
M. Polany and E. Wigner, Z. Phys. Chem. Abt. A, 139 (1928) 439.
W. E. Garner (Ed.), Chemistry of the Solid States, Butterworth, London 1955, p. 221.
W. E. Brown, D. Dollimore and A. K. Gallway in C. H. Bamforf and C. F. H. Tipper (Eds), Comprehensive Chemical Kinetics, Vol. 22, Reaction in Solid State, Elsevier, Amsterdam 1980, p. 123.
Ref. 20, p. 92.
R. D. Shannon, Trans. Faraday Soc., 60 (1964) 1902.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Masuda, Y., Iwata, K. The effect of the water vapor pressure on the kinetics of thermal dehydration of manganese(II) formate dihydrate. Journal of Thermal Analysis 44, 1013–1020 (1995). https://doi.org/10.1007/BF02547529
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02547529