Accession Number : AD0677008

Title :   MASS SPECTROMETRIC STUDY OF THE EVAPORATION OF BaMoO4 AND BaWO4 (1).

Descriptive Note : Final rept. 1 Feb 66-31 May 68,

Corporate Author : CORNELL UNIV ITHACA N Y DEPT OF CHEMISTRY

Personal Author(s) : Pupp,C. ; Yamdagni,R. ; Porter,Richard F.

Report Date : 23 OCT 1968

Pagination or Media Count : 26

Abstract : Mass spectrometric studies indicate that barium molybdate and barium tungstate salts evaporate mainly molecular BaMoO4(g) and BaWO4(g), respectively. The importance of ion fragmentation processes occurring in the mass spectrometer were established from appearance potential measurements and the variations in relative ion intensities with condensed phase composition. Third-law calculations give for the dissociation reactions: BaMoO4(g) = BaO(g) + MoO3(g), Delta-H = 129.7 plus or minus 4.0; BaMoO3(g) = BaO(g) + MoO2(g), Delta-H = 132.2 plus or minus 6.0; BaWO4(g) = BaO(g) + WO3(g), Delta-H = 148.3 plus or minus 4kcal. The heats of vaporization of BaMoO4(l) at 2000K are 83.5 and 93.7 plus or minus 4 kcal/mole, respectively. (Author)

Descriptors :   (*BARIUM COMPOUNDS, EVAPORATION), (*MOLYBDATES, EVAPORATION), (*TUNGSTATES, EVAPORATION), MASS SPECTROSCOPY, THERMOCHEMISTRY, DISSOCIATION, HEAT OF REACTION, HEAT OF VAPORIZATION

Subject Categories : Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE