ELECTROCHEMISTRY LESSON 2 ( common terms used)

Common terms used in electrolysis and explanation of the changes that take place during electrolysis


⁣Common Terms Used in Electrolysis:

Electrolyte: A substance that conducts electricity due to the presence of free ions. These ions can be dissolved in a solvent (like aqueous solutions) or molten.
Electrode: An electrical conductor in contact with an electrolyte. There are two types:

Anode: The positive electrode where oxidation occurs. Electrons flow out of the anode.
Cathode: The negative electrode where reduction occurs. Electrons flow into the cathode.


Electrolysis: The process of using electrical energy to drive a non-spontaneous chemical reaction. An external power source provides the energy to overcome the activation energy barrier of the reaction.
Electrolysis products: The substances formed at the electrodes during electrolysis. These products depend on the specific reaction occurring.
Electrolytic cell: A device used to carry out electrolysis, consisting of electrodes, an electrolyte, and a power source.
Changes During Electrolysis:
Electrolysis involves several key changes:

Electrical energy to chemical energy: The external power source provides electrical energy, which is converted into chemical energy to drive the non-spontaneous reaction.
Oxidation at the anode: Anions from the electrolyte lose electrons at the anode, undergoing oxidation. This can involve the electrode itself being oxidized or the oxidation of ions in the electrolyte.
Reduction at the cathode: Cations from the electrolyte gain electrons at the cathode, undergoing reduction.
Movement of ions: Ions in the electrolyte migrate towards the oppositely charged electrode to maintain electrical neutrality.
Formation of electrolysis products: The products of the oxidation and reduction reactions at the electrodes form the final electrolysis products.
Example: Electrolysis of water (H₂O):

Electrolyte: Aqueous solution of sodium chloride (NaCl)
Anode: 2Cl⁻ → Cl₂ + 2e⁻ (Chlorine gas is produced at the anode)
Cathode: 2H₂O + 2e⁻ → H₂ + 2OH⁻ (Hydrogen gas is produced at the cathode)
Overall reaction: 2H₂O → 2H₂ + O₂ (decomposition of water)
Note: This is a simplified example. The specific reactions and products depend on the nature of the electrolyte and the applied voltage.