In covalent compounds, atoms are bonded together by sharing electrons, forming strong covalent bonds. These electrons are localized between the atoms and cannot move freely, which inhibits the formation of mobile ions. As a result, covalent compounds exist as neutral molecules and do not dissociate into ions.
In contrast, ionic compounds, such as sodium chloride (NaCl), readily dissolve in water or melt to form solutions or molten states containing freely moving ions. These ions, such as sodium (Na+) and chloride (Cl-) ions in the case of NaCl, can carry electric current, making ionic compounds suitable for electrolysis.
When an electric current is passed through a solution or molten ionic compound, the ions are attracted to the oppositely charged electrodes. Positive ions (cations) migrate towards the negative electrode (cathode), and negative ions (anions) move towards the positive electrode (anode). This movement of ions allows for chemical reactions to occur at the electrodes, resulting in the decomposition or transformation of the compound.
In summary, covalent compounds do not undergo electrolysis because they lack free ions to conduct electricity. Electrolysis is typically applicable to ionic compounds or certain molten salts that contain mobile ions.
