Figure 3: The plots of log D’ –log [Cu] versus pH at the extraction of Cu(I) with lauric acid diluted in benzene at 298.2 K. Initial concentration of Cu(I) (M): concentration of 0.2 M lauric acid: (?) 5×10-4; (?) 2.5×10-3; (?) 5×10-3; (?) 2.5×10-2 and concentration of 0.5 M lauric acid: (¦) 5×10-4; (?) 2.5×10-3; (×) 5×10-3; (?) 2.5×10-2 .