Electrolysis:
A known volume 10-40 cm3 of the sample solution is taken in the cell and the electrolysis is permitted to proceed till the current decreases to the small value observed along with the supporting electrolyte alone. Electrolysis commonly completed within an hour. Measure Q along with the help of hydrogen-oxygen coulometer and the mass 'm' of the metal deposited is provided through the equation:
m = Mr (Q - Ib × t )/nF
where Mr is the associative atomic mass of the metal,, Q is the total quantity of electricity (coulombs) calculated along with the help of a coulometer or current time integration, Ib is the background current (amperes), t is the time of electrolysis in seconds), n is the number of electrons for the reduction and F is the Faraday constant.