Effect of Temperature on Electrophoretic Behaviour of Complex Ions of Transition Metals in Aqueous Solution of Hydrochloric Acid

Abstract

The electrophoretic behaviours of chloro-complexes of Co(II), Cu(II), Fe(III), and Ni(II) in aqueous solutions of hydrochloric acid (1 to 10 N) were studied in the temperature range from 3 to 82°C.
At intermediate hydrochloric acid concentrations, the zones of Co(II), Cu(II), and Fe(III) migrate towards the cathode when the temperature is low, while with an increase in temperature the zones are reversed in their direction and migrate towards the anode. On the other hand, the zones of Ni(II) always migrate towards the cathode at all the temperatures and hydrochloric acid concentrations studied. For the Co(II), Cu(II), and Fe(III) zones, the hydrochloric acid concentration ranges where the direction reversion appeared with increasing temperature were determined.
The results can be explained in terms of a predominant formation of higher chloro-complexes at higher temperatures.