VAPORIZATION REACTIONS OF VANADIUM(III) BROMIDE. DISSOCIATION AND DISPROPORTIONATION EQUILIBRIA, AND THE FORMATION OF VANADIUM(IV) BROMIDE

Technical Report · Tue Aug 21 04:00:00 EDT 1962

OSTI ID:4691544

McCarley, R E; Roddy, J W

The equilibria (1) VBr/sub 3/(s) = VBr/sub 2/(s) + 1/2Br/sub 2/(g) and (2) 2VBr/sub 3/(s) = VBr/sub 2/(s) + VBr/sub 4/(g) were studied over the range 644 to 805 un. Concent 85% K by transpiration in He. The expressions log p/sub mm/(Br/sub 2/(g)) = -5070/T + 5.02 and log p/sub mm/(VBr/sub 4/(g)) = -8240/T + 8.47 were derived from the measurements for (1) and (2), respectively; for (1) DELTA H/sup 0/ = 23.1 450 deg C in a 0.9 kcal/ mole and DELTA S/sup o/ = 9.8 450 deg C in a 0.4 eu, while for (2) DELTA H/sup 0/ = 37 450 deg C in a 1.3 kcal/mole and DELTA S/sup 0/ = 25.5 450 deg C in a 0.8 eu. Both transpiration in Br vapor and static pressure measurements using a glass diaphragm gauge showed the VBr/sub 3/(s) vaporized as VBr/sub 4/(g) in the presence of Br according to (3) VBr/sub 3/(s) + 1/2Br/sub 2/(g) = VBr/sub 4/(g). Data from the transpiration and diaphragm gauge measurements were in excellent agreement; the transpiration measurements gave for (3) log K (atm/sup 1/2/) = -3455/T + 5.22 and DELTA F/sup 0/ = 15.80 x 10/sup 3/ -23.9T for T = 515 to 585 un. Concent 85% K. Solid VBr/ sub 4/ was isolated by condensation of the vapor at -78 un. Concent 85% C, and was found to be stable at -45 un. Concent 85% C. At higher temperatures the soiid decomposed to VBr/sub 3/(s) and Br. (auth)

• Research Organization: Ames Lab., Ames, Iowa
• DOE Contract Number: W-7405-ENG-82
• NSA Number: NSA-17-023293
• OSTI ID: 4691544
• Report Number(s): IS-533
• Country of Publication: United States
• Language: English

Related Subjects

BROMINE
CHEMISTRY
DECOMPOSITION
DISPROPORTIONATION
GLASS
HELIUM
HIGH TEMPERATURE
INERT GASES
LIQUEFYING
LOW TEMPERATURE
MEMBRANES
SEPARATION PROCESSES
TEMPERATURE
THERMODYNAMICS
VANADIUM BROMIDES
VAPORS