What are the observations during the electrolysis of water?

During the electrolysis of water, hydrogen gas is produced at the cathode and oxygen gas at the anode.

When water undergoes electrolysis, it is split into its constituent elements, hydrogen and oxygen. This process is facilitated by the addition of an electrolyte, usually a small amount of sulphuric acid, to increase the conductivity of the water. The water is then subjected to an electric current, which breaks the bonds between the hydrogen and oxygen atoms.

At the cathode (the negative electrode), hydrogen ions (H+) gain electrons to form hydrogen gas (H2). This is a reduction reaction, as the hydrogen ions are gaining electrons. You can observe this as bubbles of gas forming at the cathode.

At the anode (the positive electrode), oxygen ions (O2-) lose electrons to form oxygen gas (O2). This is an oxidation reaction, as the oxygen ions are losing electrons. You can observe this as bubbles of gas forming at the anode.

The ratio of hydrogen to oxygen produced is approximately 2:1, which is the same as the ratio of hydrogen to oxygen in a water molecule (H2O). This can be confirmed by collecting the gases produced and measuring their volumes.

The electrolysis of water is a key process in the field of electrochemistry and is used in various industrial processes. It's also a fundamental experiment in IGCSE Chemistry, demonstrating the principles of electrolysis, oxidation, reduction, and the composition of water.