Before understanding the principle of electrolysis, we should know what is electrolyte or definition of electrolyte
Definition of Electrolyte
An electrolyte is such a chemical that's atoms are normally closely bonded together but when it is dissolved in water, its molecules split up into positive and negative ions. The positively charged ions are referred as cations whereas negatively charged ions are referred as anions. Both cations and anions move freely in the solution.
Principle of Electrolysis
As discussed in the definition of electrolyte, whenever any electrolyte gets dissolved in water, its molecules split into cations and anions moving freely in the electrolytic solution. Now two metal rods are immersed in the solution and an electrical potential difference applied between the rods externally preferably by a battery . These partly immersed rods are technically referred as electrodes. The electrode connected with negative terminal of the battery is known as cathode and the electrode connected with positive terminal of the battery is known as anode. The freely moving positively charged cations are attracted by cathode and negatively charged anions are attracted by anode. In cathode, the positive cations take electrons from negative cathode and in anode, negative anions give electrons to the positive anode. For continually taking and giving electrons in cathode and anode respectively, there must be flow of electrons in the external circuit of the electrolytic. That means, electric current continues to circulate around the closed loop created by battery , electrolytic and electrodes. This is the most basic principle of electrolysis.
Electrolysis of Copper Sulfate
The process described above is known as electrolysis. In the above process, after taking electrons the neutral copper atoms get deposited on the cathode. At the same time, SO4 reacts with copper anode and becomes CuSO4 but in water it can not exist as single molecules instead of that CuSO4 will split into Cu+ +, SO4 − − and dissolve in water. So it can be concluded that, during electrolysis of copper sulfate with copper electrodes, copper is deposited on cathode and same amount of copper is removed from anode.