Ionic compounds play a crucial role in electrolysis due to their ability to contain ions that can move and carry an electric charge when in a molten state or dissolved in a solution.

To elaborate, electrolysis is a process that utilizes an electric current to drive a non-spontaneous chemical reaction. This process necessitates a substance capable of conducting electricity, making ionic compounds ideal candidates. These compounds consist of positively charged ions (cations) and negatively charged ions (anions). When ionic compounds are either dissolved in water or melted, the ions are liberated and can move freely. This mobility of ions is what facilitates the conduction of electricity.

During electrolysis, the electric current is transported by the movement of ions towards the electrodes. Cations migrate towards the negative electrode, known as the cathode, while anions travel towards the positive electrode, called the anode. Upon reaching the electrodes, these ions either gain or lose electrons, resulting in their transformation into new substances. This principle lies at the core of the electrolysis process.

For instance, consider sodium chloride ($\text{NaCl}$), an ionic compound. When dissolved in water or melted, sodium ions ($\text{Na}^+$) will move towards the cathode, whereas chloride ions ($\text{Cl}^-$) will head towards the anode. At the cathode, sodium ions gain electrons, converting into sodium atoms, while at the anode, chloride ions lose electrons, resulting in the formation of chlorine molecules. This example illustrates how ionic compounds facilitate electrolysis to yield new substances.

In conclusion, ionic compounds are vital to the process of electrolysis because they contain mobile ions capable of carrying an electric charge, thereby enabling the electrolysis process to take place.