Applications:

Controlled cathode potential is extremely meaningful in the separation of quantitative determination of metallic species.

Successive deposition of the metals

A mixture of copper, lead, bismuth, cadmium, zinc and tin could is determined through successive deposition of the metals on a platinum cathode. First copper is deposited through managing the cathode potential at -0.2V vs. SCE. After weighing the cathode, the copper plated cathode is used to deposit bismuth at a potential of -0.4V. After that lead is deposited over the similar cathode through managing a cathodic potential of -0.6V.

All these three components are deposited from a neutral solution holding tartarate ions, that forms complex along with tin (IV) and avoid its deposition. While lead deposition is done, the solution is made strongly ammoniacal and zinc and cadmium are deposited successively at -l.2V and -l.5V respectively. At last, the solution is acidified to decompose the tin-tartarate complex and tin is deposited at a potential of - 0.65V by using a fresh cathode.