Titrimetric determination of copper(II) with iron(II) in the presence of thiocyanate and oxalate
Copper(II) was determined titrimetrically with a standard iron(II) solution at pH 3.95–4.92 in the presence of potassium thiocyanate and sodium oxalate. Both potentiometric and visual (using cacotheline as indicator) methods were employed in detecting the equivalence point. The method was extended to the determination of copper in brass and Cu-Ni alloy and the effects of pH, oxalate and thiocyanate concentrations were studied. The formal redox potentials of copper(II)-copper(I) and iron(III)-iron(II) couples were measured in the presence of thiocyanate and oxalate at various pH values.