Browsing by Author "Kassa, Kinfe"

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    Synthesis of Pyrophosphate and Selenooyrophosohate Based Cation Exchangerso and their Selected Application
    (Addis Ababa Universty, 1993-01) Kassa, Kinfe; Retta, Negussie (PhD)
    The synthesis of ceriurn(lV) pyrophosphate and cerium(IV) selenopyroposphate by mixing aqueous solution of tetrasodium pyrophosphate with ceriurn(IY) sulfate in 1 M sulfuric acid and tetrasodium pyrophosphate, sodium selenite with cerium(IV) sulfate, respectively, are reported .. Elemental analyses showed that Ce: P04 3 - ratio is 1:2 for ceriurn(IY) pyrophosphate and 0.47:1:0.03, Ce : P04 3 - : 3e03 2 - for ceriurn(IY) selenopyrophosphate. IR spectra of both exchangers showed five peaks at frequencies Ca. 3400, 1600,1200,980,200-300 cm- 1 , which are due to water and hydroxyl group, lattice water, phosphate group, P-O-P and Ce-O stretching vibrations, respectively. The hydrogen ion liberation capacities of ceriurn(rV) pyrophosphate and cerium(IV) selenopyrophosphate were found to be 1.40 and 1.15 meq/g respectively in neutral salt, and about 3 meq/g at pH 8 with ion uptake measurement. The chemical stability, pH titration, X-ray diffraction, an~ ion uptake have been studied. On the basis of distribution coefficient obtained at different pH for some metals column separation of this same metal ions was performed. The solid electrical conductivity of the exchangers was also determined.