Enstatite Enthalpy

Enneagold heteronuclear cluster compounds. X-ray crystallography, 39 375-376 Enniatin-B, 42 119-120 Enolase, arsonomethyl analogue, 44 205-206 Enstatite, crystal structure of, 4 51 Enthalpy... 

Koziol A. M. and Newton R. C. (1995) Experimental determination of the reactions magnesite -F quartz = enstatite -F CO2 and magnesite = periclase -F CO2 and the enthalpies of formation of enstatite and magnesite. Am. Mineral. 80, 1252-1260. 

The enthalpy of formation of enstatite (—f, 548.9 kJ mol ) is less than the total enthalpy of formation of the MgO and Si02 oxides ( — 1, 512.2 kJ mol ). Therefore, formation of a more stable product in condensation of vapours appears reasonable. There is nothing unexpected either in condensation of the excess Si02 molecules (above the MgO molecules present) in the form of an X-ray amorphous residue, considering the fairly high oversaturation of Si02 vapour (see Table 2.5). 

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