During the electrolysis of water, what is released at the cathode?

During the electrolysis of water, the process involves the decomposition of water molecules (H₂O) into their constituent elements, which are hydrogen and oxygen. This occurs when an electric current is passed through water, often using an electrolyte to facilitate the conduction of electricity.

At the cathode, which is the negative electrode, reduction occurs. In the case of the electrolysis of water, positive hydrogen ions (H⁺), attracted to the cathode, gain electrons to form hydrogen gas (H₂). This reaction can be summarized as:

[ 2H^+ + 2e^- \rightarrow H_2(g) ]

Thus, hydrogen gas is liberated at the cathode during the electrolysis of water. The process also generates oxygen gas at the anode, which is the positive electrode, but at the cathode, it is specifically hydrogen that is produced.

Options such as chlorine, oxygen, and water do not represent the products formed at the cathode during this specific electrolysis process. Chlorine would be produced if electrolysis involved a salt solution, while oxygen is found at the anode, and water is the substance being electrolyzed rather than a product generated at the cathode.