Daftar Isi: Ternary Complex-Influence of Oxalic Acid on Vanadium(V) Determination with 4-Sulpho-2- Aminobenzenethiol in Aqueous Solution

Daftar Isi:

Department of Chemistry, Jadavpur University, Calcutta-700 032 Manuscript received 15 December 1980, revised 1 December 1981, accepted 2 February 1982 Vanadium(V) forms a ternary blue violet complex with oxalic acid and 4-sulpho-2-aminobeneenetbiol. The complex is formed in the concentration range of 0.24 M to 0.64 M hydrochloric acid. It absorbs maximum at 560 nm and is stable for 5 hr at room temperature. The system. obeys Beer's law from 1 to 36 ppm. The molar absorptivity and Sandell's sensitivity values are 1.6 x I 0 3 1.mole-1cm-1 and 0.0302 βg cm-2 V(V). A 50-fold excess of Co(II), Ni(II), Mn(II), Zn(II), Cd(II), Bi(III), Sn(II),Pb(II), Ti(II), Mo(VI), W(VI), U(VI) and tartrate, fluoride, acetate, citrate, EDTA, oxalate do not interfere. The mixed-ligand complex is formed in 1 : 1 : 1 ratio of V : oxal : thiol. The overall stability constant of the vanadium complex is 6.40 at 29\(\pm\)1°. The photometric method has been found to be very selective in presence of titanium(V) and other metal ions. Iron(III) and iron(II) strongly interfered.