During electrolysis, the cathode serves as the site where cations are attracted and reduction reactions take place.

To elaborate, electrolysis is a process that employs an electric current to drive a chemical reaction that would not occur spontaneously. This process occurs within an electrolytic cell, which consists of two electrodes: an anode and a cathode. The cathode is defined as the electrode where reduction happens, making it the location to which cations (positively charged ions) migrate.

Cations are drawn to the cathode due to its negative charge. Upon reaching the cathode, these cations gain electrons and undergo reduction. This reduction process can be represented by the general equation:

For instance, when copper ions ($\text{Cu}^{2+}$) are present in the electrolyte, they will be attracted to the cathode, where they can gain two electrons and be reduced to neutral copper atoms ($\text{Cu}$).

The specific reactions that occur at the cathode can vary based on the electrolyte used and the materials of the electrodes. For example, if the electrolyte is a sodium chloride ($\text{NaCl}$) solution, the cations present will include sodium ions ($\text{Na}^+$) and hydrogen ions ($\text{H}^+$). If the cathode is made of an inert material, such as platinum or graphite, the hydrogen ions are preferentially reduced, resulting in the formation of hydrogen gas. Conversely, if the cathode is composed of a more reactive metal, such as iron, the sodium ions may be reduced instead.

In summary, the cathode plays a vital role in the electrolysis process as the site of reduction reactions. It attracts cations from the electrolyte, which then gain electrons and are transformed into their neutral forms. While the specific reactions that occur at the cathode can differ, the fundamental process of reduction remains consistent throughout.