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Stability and Thermodynamics of Glutamic Acid Complexes with Cerium(III) and Yttrium(III)
Author(s) -
Sekhon B. S.,
Chopra S. L.
Publication year - 1974
Publication title -
israel journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.908
H-Index - 54
eISSN - 1869-5868
pISSN - 0021-2148
DOI - 10.1002/ijch.197400084
Subject(s) - yttrium , cerium , chemistry , ionic strength , titration , inorganic chemistry , aqueous solution , stability constants of complexes , lanthanide , ionic bonding , nuclear chemistry , ion , organic chemistry , oxide
Stepwise stability constants of the complexes of glutamic acid with cerium(III) and yttrium (III) have been determined by the Calvin‐Bjerrum pH titration technique as used by Irving and Rossotti in aqueous solution at 25° and 45°C. The values of log β 2 for cerium complexes are: 9.75 (μ = 0.1), 9.57 (μ = 0.2), 9.38 (μ = 0.3) at 25°C; and 10.90 (μ = 0.1), 10.74 (μ = 0.2), 10.64 (μ = 0.3) at 45°C. The log β 2 values for yttrium complexes at μ = 0.1 are 9.98 and 9.77 at 25° and 45°C respectively. The values of log β 2 (μ = 0.0) for cerium complexes are 10.21 and 11.24 at 25° and 45°C respectively. The increasing ionic strength of the medium decreases the stabilities of cerium complexes which are also more stable at 45° than 25°C whereas yttrium complexes are less stable at 45°C. The values of AH and ΔS are positive for cerium complexes whereas in the case of yttrium complexes, the values of ΔH are negative and those of ΔS are positive.