Organic Solvent Effect, Thermodynamic Study and Synergism Behavior for Extraction Efficiency of Cobalt (II) Complex with 1-[2-Pyridyl Azo] -2-Naphthol

Abstract

After pinpoint all optimum conditions for extraction Cobalt(II) as ion pair association complex or chleated complex with complexing agent 1-[2-pyridyl azo] -2-naphthol which dimonirtrate λ max for complex extracted was (446nm.) more stable complex formation was at pH= 7 and 60 µg Co(II)/5ml with 1×10 -4 M 1-[2-pyridyl azo] -2-naphthol[PAN] dissolved in chloroform and shaking time 10 minutes. The stoichiometry of complex extracted to the organic phase was 1:1 metal : PAN [Co(PAN) + Cl -] or [Co(PAN)] + (Cl -).Extraction method was endothermic as well as thermodynamic parameters after calculated was ∆H ex = 0.0149 KJmol -, ∆G ex = -58.81 KJ mol -and ∆S ex = 176.55 J mol -. Synergism study show from the slope is appear there is one molecule of TBP or MIBK participated in the structure of complex extracted to the organic phase.