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  • 1
    Electronic Resource
    Electronic Resource
    The hydrolysis and fluoride complexation behavior of Fe(III) at 25°C and 0.68 molal ionic strength (1996)
    Springer
    Journal of solution chemistry 25 (1996), S. 773-785 
    Details
    ISSN: 1572-8927
    Keywords: Iron(III) ; ferric ; hydrolysis ; fluoride ; complexation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Fe(III) hydrolysis and fluoride complexation behavior was examined in 0.68 molal sodium perchlorate at 25°C. Our assessment of the complexation of Fe(III) by fluoride ions produced the following results: logFβ1 = 5.155, logFβ2 = 9.107, logFβ3 = 11.96, logFβ4 = 13.75, where logFβn = 5.155=[FeF n (3-n)+ ][Fe3+]−1[F−]−n. The stepwise fluoride complexation constants,FK n+1, obtained in our work (where logF K n+1 =logFβn) indicate that K n+1/K n =0.072±0.01. Formation constants for equilibria, Fe3++nH2O⇌Fe(OH) n (3−n)+ +nH+, expressed in the form β n * [Fe(OH) n (3-n)+ ][H+]n ,[Fe 3+]-1, were estimated as β 1 * = −2.754, and β 2 * ≤ −7. Our study indicates that the results of previous hydrolysis investigations include very large overestimates of Fe(OH) 2 + formation constants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00973784
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  • 2
    Electronic Resource
    Electronic Resource
    Comprehensive Investigation of Yttrium and Rare Earth Element Complexation by Carbonate Ions Using ICP–Mass Spectrometry (1998)
    Springer
    Journal of solution chemistry 27 (1998), S. 803-815 
    Details
    ISSN: 1572-8927
    Keywords: Rare earth ; complexation ; carbonate ; ICP–MS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Carbonate stability constants for yttrium and all rare earth elements have been determined at 25°C and 0.70 molal ionic strength by solvent exchange and inductively coupled plasma–mass spectrometry (ICP–MS). Measured stability constants for the formation of $${\text{MCO}}_3^ +$$ and $${\text{M}}\left( {{\text{CO}}_{\text{3}} } \right)_2^--$$ from M3+ are in good agreement with previous direct measurements, which involved the use of radio-chemical techniques and trivalent ions of Y, Ce, Eu, Gd, Tb, and Yb. Direct ICP–MS measurements of $${\text{MCO}}_3^ +$$ and $${\text{M}}\left( {{\text{CO}}_{\text{3}} } \right)_2^--$$ formation constants are also in general agreement with modeled stability constants for the metals La, Pr, Nd, Sm, Dy, Ho, Er, Tm, and Lu, based on linear-free energy relationship (LFER). The experimental procedures developed in this work can be used for assessing the complexation behavior of other geochemically important ligands such as phosphate, sulfate, and fluoride.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022677119835
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  • 3
    Electronic Resource
    Electronic Resource
    Ultraviolet spectroscopic study of ferric hydroxide complexation (1978)
    Springer
    Journal of solution chemistry 7 (1978), S. 373-383 
    Details
    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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  • 4
    Electronic Resource
    Electronic Resource
    Interaction of B $$(OH)_3^0 $$ and $$HCO_3^ - $$ in Seawater: Formation of B $$(OH)_2 CO_3^ - $$ (1997)
    Springer
    Aquatic geochemistry 3 (1997), S. 345-356 
    Details
    ISSN: 1573-1421
    Keywords: boron ; boric acid ; carbonate ; CO2 system ; complexation ; spectrophotometric pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Boron is known to interact with a wide variety of protonated ligands(HL) creating complexes of the form B(OH)2L-.Investigation of the interaction of boric acid and bicarbonate in aqueoussolution can be interpreted in terms of the equilibrium $$B(OH)_3^0 + HCO_3^ - \rightleftharpoons B(OH)_2 CO_3^ - + H_2 O$$ The formation constant for this reaction at 25 °C and 0.7 molkg-1 ionic strength is $$K_{BC} = \left[ {B(OH)_2 CO_3^ - } \right]\left[ {B(OH)_3^0 } \right]^{ - 1} \left[ {HCO_3^ - } \right]^{ - 1} = 2.6 \pm 1.7$$ where brackets represent the total concentration of each indicatedspecies. This formation constant indicates that theB(OH)2 $$CO_3^ - $$ concentration inseawater at 25 °C is on the order of 2 μmol kg-1. Dueto the presence of B(OH)2 $$CO_3^ - $$ , theboric acid dissociation constant ( $$K\prime _B $$ ) in natural seawaterdiffers from $$K\prime _B $$ determined in the absence of bicarbonate byapproximately 0.5%. Similarly, the dissociation constants of carbonicacid and bicarbonate in natural seawater differ from dissociation constantsdetermined in the absence of boric acid by about 0.1%. Thesedifferences, although small, are systematic and exert observable influenceson equilibrium predictions relating CO2 fugacity, pH, totalcarbon and alkalinity in seawater.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009633804274
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    Paper (German National Licenses)
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