Comparison between 1- and 2-Naphthoic Acids as an Extracting Agent for Cobalt(II), Nickel(II) and Copper(II)

Abstract

The extraction of cobalt(II), nickel(II) and copper(II) with 1- and 2-naphthoic acids was carried out using benzene and 1-octanol as a solvent at 25°C and a 0.1mol dm^-3 constant ionic strength in the aqueous phase (NaClO₄). Although just a slight difference in the partition behavior of 1-naphthoic and 2-naphthoic acids was detected for both benzene and 1-octanol solvent systems, it has been found that between these isomers there were pronounced differences in the extraction equilibria of cobalt(II), nickel(II) and copper(II) naphthoates for both benzene and 1-octanol solvent systems. 1-Naphthoic acid was found to be significantly superior to 2-naphthoic acid not only in the extractability of these metal ions, but also in the solubility into both benzene and 1-octanol solvents.