What is the function of the cathode in an electrolytic cell ?
1 Answer
The cathode is where reduction occurs in an electrolytic cell.
Explanation:
(BBC )
In the case of copper(II) chloride solution the +ve copper(II) ions are attracted to the cathode and discharged.
The numeral (II) tells us that the copper ion has a 2+ charge so will require 2 moles of electrons to form a neutral copper atom.
The half equation will therefore be:
So the charge on the ion decides how many moles of electrons are needed. E.g aluminium is extracted from its ore by the electrolysis of molten alumina. The half equation is:
In some cases for aqueous solutions, too much energy is required to discharge the metal ion. In the case of aqueous sodium chloride water is reduced instead:
This process forms the basis of the chlor - alkali industry.