Extraction of Cu(II) with decanoic acid into 1-octanol

Abstract

Extraction of Cu(II) with decanoic acid in 1-octanol was carried out at 25°C and aqueous ionic strength of 0.1 mol dm −3 (NaClO 4). Monomeric and dimeric copper decanoates are responsible for the extraction at a total copper concentration of 5×10 −3 mol dm −3 and decanoic acid concentration of 0.5–2.0 mol dm −3. Species involved in the organic phase are CuA 2, CuA 2HA, Cu 2A 4 and Cu 2A 4(HA) 2. Adduct formation and dimerization of copper decanoates in the 1-octanol phase can be formulated as: CuA 2+HA ⇌ K ad, monomer CuA 2HA CuA 2+2HA ⇌ β ad, dimer CuA 4(HA) 2 2 CuA 2 ⇌ K dim−t CuA 4 2 CuA 2HA ⇌ K dim−2 CuA 4(HA) 2 with log K Prmad, monomer =−0.24±0.04, log β ad, dimer=−0.41±0.04, log K dim-1=3.46±0.06 and K dim-2=3.53±0.06, respectively.