ISSN:
1572-8927
Keywords:
Ferric
;
hydrolysis
;
ionic strength
;
temperature
;
enthalpy
;
ferric hydroxide
;
ultraviolet
;
spectroscopic
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Ultraviolet absorbance spectra of ferric ions in 0.68m NaClO4 were studied as a function of pH at 4.0, 14.9, and 25.0°C. The results provided an evaluation of the stability constant for the formation of FeOH2+ which is *β1=[FeOH +][H +]/[Fe 3+]. The enthalpy change for the reaction Fe3++H2O⇌ FeOH2++H+ was calculated as 10.0±0.3 kcal-mole−1. Increasing temperature was also found to promote the reaction Fe3++2H2O⇌ Fe(OH) 2 + +2H+. Our results were combined with the results of other to produce an expression describing the first hydrolysis equilibrium at ionic strengths between 0 and 3m and temperatures between 4.0 and 45.0°C at 1 atm total pressure. At 25°C and 0.68m the ionic strength *β1=1.90×10-3
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00662897
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