What Is Electrolysis?
Electrolysis is a chemical process that uses a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. The term literally means 'to break up with electricity.' The process takes place in a device called an electrolytic cell, which contains an electrolyte and two electrodes (an anode and a cathode).
Section 2: How Does Electrolysis Work?
An electrolyte, a substance with free-moving ions (like salt dissolved in water), is required for electrolysis. Two electrodes, a positive anode and a negative cathode, are submerged in the electrolyte and connected to a power source. When current is applied, positive ions (cations) are attracted to the negative cathode, where they gain electrons (reduction). Negative ions (anions) are attracted to the positive anode, where they lose electrons (oxidation).
Section 3: A Practical Example
A classic example is the electrolysis of water (H₂O). When electricity is passed through water containing a small amount of an electrolyte, the water decomposes into its constituent elements. Hydrogen gas (H₂) is produced at the cathode, and oxygen gas (O₂) is produced at the anode. This is a common method for producing high-purity hydrogen.
Section 4: Importance and Applications
Electrolysis is crucial for many industrial applications. It is used in electroplating to coat objects with a thin layer of metal, such as chrome-plating car parts for protection and appearance. It is also essential for extracting highly reactive metals like aluminum, sodium, and magnesium from their ores and for producing industrial chemicals like chlorine gas.