Thermodynamics of the gaseous zirconium iodides

Journal Article · Fri Sep 01 04:00:00 EDT 1978 · J. Electrochem. Soc.; (United States)

DOI:https://doi.org/10.1149/1.2131712· OSTI ID:5557133

Kleinschmidt, P D; Cubicciotti, D; hildenbrand, D L

The gaseous zirconium iodides ZrI/sub 4/, ZrI/sub 3/, ZrI/sub 2/, and ZrI, generated by the reaction of HI(g) with Zr(s) at elevated temperatures, were identified and characterized thermochemically by Knudsen cell mass spectrometry. Gaseous ZrI/sub 4/ was the major reaction product up to about 1300/sup 0/K; above this temperature, atomic I became the major product, with minor amounts of the lower Zr iodides appearing as the temperature was progressively raised. From an analysis of equilibrium data, the following enthalpies of formation were deduced; ..delta.. Hf/sup 0//sub 298/(ZrI/sub 3/,g) = - 30.8 +- 1.5 kcal/mole, ..delta..Hf/sup 0//sub 298/(ZrI/sub 2/, g) = 32.6 +- 4.0 kcal/mole, and ..delta..Hf/sup 0//sub 298/(ZrI, g) = 96.3 +- 2.8 kcal/mole. Individual bond dissociation energies evaluated from the enthalpy data are close to the average value in ZrI/sub 4/. The new thermochemical data are consistent with observations on the iodide process for refining impure zirconium whereas earlier estimates are not. 4 figures, 7 tables.

• Research Organization: SRI International, Menlo Park, CA
• OSTI ID: 5557133
• Journal Information: J. Electrochem. Soc.; (United States), Journal Name: J. Electrochem. Soc.; (United States) Vol. 125:9; ISSN JESOA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
CHEMICAL REACTION YIELD
ELEMENTS
ENTHALPY
FLUID FLOW
FLUIDS
GAS FLOW
GASES
HALIDES
HALOGEN COMPOUNDS
HALOGENS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
IODIC ACID
IODIDES
IODINE
IODINE COMPOUNDS
KNUDSEN FLOW
MASS SPECTROSCOPY
METALS
NONMETALS
PHYSICAL PROPERTIES
PROCESSING
REFINING
SPECTROSCOPY
THERMOCHEMICAL PROCESSES
THERMODYNAMIC PROPERTIES
THERMODYNAMICS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
VERY HIGH TEMPERATURE
YIELDS
ZIRCONIUM
ZIRCONIUM ALLOYS
ZIRCONIUM COMPOUNDS
ZIRCONIUM IODIDES