Back
 AJAC  Vol.2 No.2 , May 2011
Study on Thermodynamics and Kinetics for the Reaction of Magnesium Diboride and Water by Microcalorimetry
Abstract: An exothermic reaction between MgB2 and water was observed in our laboratory at high temperature, although no obvious reaction occurred at room temperature. The reaction process of MgB2 and water was therefore studied by using microcalorimetry. The results showed that the reaction enthalpies of MgB2 with water and the formation enthalpies of MgB2 at T = (323.15, 328.15, 333.15 and 338.15) K are (–313.15, –317.85, –322.09, –329.27) kJ?mol–1, and (–238.96, –237.73, –236.50, –234.30) kJ●mol–1, respectively. The standard enthalpy of formation and standard molar heat capacity of MgB2 obtained by extrapolation method are –245.11 kJ●mol–1 and 246 J●mol–1●K–1, respectively. The values of activation energy E, pre-exponential factor A and the reaction order for the reaction of MgB2 and water over the temperature range from 323.15 K to 338.15 K are 50.80 kJ●mol–1, 104.78 s–1 and about 1.346, respectively. The positive values of ΔG≠ and ΔH≠ and negative value of ΔS≠ indicate that the reaction can take place easily above 314.45 K.
Cite this paper: nullF. Zhao, X. Xing, C. Xiao, R. Hu, L. Xue, H. Gao, L. Xiao and T. An, "Study on Thermodynamics and Kinetics for the Reaction of Magnesium Diboride and Water by Microcalorimetry," American Journal of Analytical Chemistry, Vol. 2 No. 2, 2011, pp. 270-275. doi: 10.4236/ajac.2011.22033.
References

[1]   J. Schmidt, W. Schnelle, Y. Grin and R. Kniep, “Pulse Plasma Synthesis and Chemical Bonding in Magnesium Diboride,” Solid State Sciences, Vol. 5, No. 4, 2003, pp. 535-539. doi:10.1016/S1293-2558(03)00026-8

[2]   A. O’Brien, B. Villegas and J. Gu, “Sputtered Magnesium Diboride Thin Films: Growth Conditions and Surface Morphology,” Physica C, Vol. 496, 2009, pp. 39-43.

[3]   G. Amico, A. Trolio, A. Morone, S. Orlando and A. Santagata, “Optical Characterization of Magnesium Diboride plasma Plume Induced by Pulsed Laser Ablation,” Applied Surface Science, Vol. 208-209, 2003, pp. 96-100. doi:10.1016/S0169-4332(02)01342-9

[4]   T. Prikhna, W. Gawalek, Y. Savchuk, N. Sergienko and V. Moshchil, “High-Pressure–High-Temperature Synthesis of Magnesium Diboride with Different Additions,” Physica C, Vol. 460-462, 2007, pp. 595-597. doi:10.1016/j.physc.2007.04.110

[5]   C. Dancer, P. Mikheenko, A. Bevan, J. Abell, J. Todd and C. Grovenor, “A Study of the Sintering Behaviour of Magnesium Diboride,” Journal of the European Ceramic Society, Vol. 29, No. 9, 2009, pp. 1817-1824. doi:10.1016/j.jeurceramsoc.2008.09.025

[6]   Z. Cheng, X. Wang, A. Pan, H. Liu and S. Dou, “Characterization and Growth of Magnesium Diboride Single Crystals,” Journal of Crystal Growth, Vol. 263, 2004, pp. 218-222.

[7]   R. Ribeiro, S. Budko, C. Petrovic and P. Canfield, “Carbon Doping of Superconducting Magnesium Diboride,” Physica C, Vol. 384, No. 3, 2003, pp. 227-236. doi:10.1016/S0921-4534(02)02331-6

[8]   R. King, “Chemical Bonding Topology of Superconductors 5. The similarities between Magnesium Diboride and Cuprate Superconductors and the Role of Subvalent Magnesium,” Polyhedron, Vol. 21, No. 23, 2002, pp. 2347-2350. doi:10.1016/S0277-5387(02)01183-X

[9]   S. Bruttia, G. Balduccia, G. Gigli, A. Ciccioli, P. Manfrinetti and A. Palenzon, “Thermodynamic and Kinetic Aspects of Decomposition of MgB2 in Vacuum: Implications for Optimization of Synthesis Conditions,” Journal of Crystal Growth, Vol. 289, 2006, pp. 578-586.

[10]   V. Marthada, “The Enthalpy of Solution of SRM 1655 (KCl) in H2O,” Journal of Research of the National Bureau of Standards, Vol. 85, No. 6, 1980, pp. 467-481.

[11]   S. Gao, S. Chen, B. Jiao, Y. Ren, R. Hu, F. Zhao and Q. Shi, “Thermochemistry on Coordination Behavior of Lanthanum Chloride Hydrate with Diethylovm Diethyldithiocarbamate,” Acta Chim Sin (in Chinese), Vol. 61, 2003, pp. 2020-2024.

[12]   R. Z. Hu and Q. Z. Shi, “Thermal Analysis Kinetics (in Chinese),” Science Press, Beijing, 2001.

 
 
Top