Introduction
Electrolysis of water is a process that uses electric current to split water into hydrogen and oxygen gases. This process occurs in an electrolytic cell, where electrodes are placed in water and connected to a power supply.
Gas Liberated at the Anode
- At the anode (positive electrode), oxygen gas is liberated.
- The half-reaction occurring at the anode can be written as:
\[ 2H_2O(l) \rightarrow O_2(g) + 4H^+(aq) + 4e^- \]
- This reaction shows that water molecules are oxidized, resulting in oxygen gas and hydrogen ions.
Gas Liberated at the Cathode
- At the cathode (negative electrode), hydrogen gas is liberated.
- The half-reaction occurring at the cathode can be written as:
\[ 4H^+(aq) + 4e^- \rightarrow 2H_2(g) \]
- This reaction indicates that hydrogen ions gain electrons (reduction) to form hydrogen gas.
Overall Reaction
- The overall balanced equation for the electrolysis of water is:
\[ 2H_2O(l) \rightarrow 2H_2(g) + O_2(g) \]
- This equation reflects the stoichiometric relationship between the volumes of hydrogen and oxygen produced.
Conclusion
- The electrolysis of water liberates hydrogen gas at the cathode and oxygen gas at the anode.
- This process not only demonstrates the principles of electrolysis but also highlights the importance of water as a source of clean energy through hydrogen production.