Why can't we use water in electrolytic cell during producing aluminium ?
You obtain the electrolysis products of H2O and not Al.
We cannot use water in an electrolytic cell during the production of aluminum because of the high reactivity of aluminum with water. Aluminum has a strong affinity for oxygen, and when it comes into contact with water, it forms aluminum oxide (Al2O3) and produces hydrogen gas. This reaction occurs spontaneously and can cause the electrolytic cell to become uncontrollable and inefficient. Additionally, aluminum oxide forms a protective layer on the surface of the aluminum, which acts as a barrier and prevents further reactions from occurring.
To produce aluminum through the electrolytic process, an electrolyte called cryolite is used instead of water. Cryolite is a mineral compound that has a lower melting point than aluminum oxide. By using cryolite, the temperature required for the electrolysis process is significantly reduced, making it more energy-efficient.
To understand why water cannot be used, one needs to consider the properties and reactivity of aluminum and its compounds, as well as the specific requirements of the electrolytic process used to produce aluminum.