Question

How do electrolysis apparatus work?

Answer 1

The electrolysis apparatus contains an electrolytic cell where two electrodes are present one is anode and one is cathode. Both the electrodes are connected to a direct source. The electrolytic cell is filled with electrolytic solution.

Complete step by step answer:
The term electrolysis was first given in the 19th century by Michael Faraday.
The electrolysis is defined as the technique where the decomposition of ionic compounds into their elemental state takes place by passing the electric current. The process of electrolysis is performed in an electrolytic cell which contains two electrodes. The two electrodes are connected to direct source. The two electrodes are cathode and anode. Cathode are negatively charged and anode are positively charged.
The cations are reduced at cathode and anions are oxidized at the anode.
Example: Molten sodium chloride can be decomposed to sodium and chlorine atoms.
Electrolysis is performed in a vessel called an electrolytic cell which contains two electrodes: cathode and anode which is directly connected to the source and an electrolyte used is an ionic compound which is either in molten form or in a dissolves form.
Electrolysis process: In the process, interchange of ions and atoms is done due to the addition or removal of electrons from the external circuit. When the electricity is passed, the cations move to the cathode, take electrons from the cathode and discharge into the neutral atom. The neutral atom if it is a solid gets deposited on the cathode and if it is gas moves upwards. At the same time the anions give their extra electrons to the anode and get oxidized to neutral atoms at the anode. The electrons which are released by the anions travel across the circuit and move to the cathode completing the circuit. The oxidation reaction takes place at the anode and the reduction reaction takes place at the cathode.
Let’s take the example of sodium chloride, when the electric current is passed through the molten sodium chloride, the sodium ion moves to the cathode from where it takes an electron to form a sodium atom. Chloride ion moves to the anode and gives it electrons and forms a chlorine atom which combines with another chlorine atom to form chlorine molecules.
At cathode: $N{a^ + }(in\;electrolyte) + {e^ - }(from\;cathode) \to Na$
At anode: $C{l^ - }(from\;electrolyte) \to {e^ - } + Cl \to C{l_2}$

Note: The electrolysis process can also be used indirectly in the metallurgy of alkali and alkaline earth metals, deposition of metals, preparation of compounds, purification of metals.