Definition of Electrode
Electrodes are conductors through which electric current enters or leaves an electrochemical cell. They facilitate chemical reactions by providing a surface for electron transfer.
Definition of Cathode
The cathode is the electrode where reduction occurs, meaning it gains electrons during a chemical reaction. In electrolysis, it is negative, attracting cations.
Definition of Anode
The anode is the electrode where oxidation takes place, resulting in the loss of electrons. In electrolysis, it is positive, attracting anions.
Key Functions of Electrodes
- Conductivity: Electrodes must have high conductivity to efficiently transfer electrons.
- Material Composition: Common materials include graphite, platinum, and metals, chosen based on the specific reaction.
- Surface Area: A larger surface area enhances the reaction rate by providing more space for electron transfer.
Electrode Reactions
- At the Cathode:
- Electrons are added to species in a solution.
- Reduction reactions occur, such as metal ions gaining electrons to become solid metal.
- At the Anode:
- Electrons are removed from species, leading to oxidation.
- Common reactions include the loss of electrons from metals or the breakdown of compounds.
Applications of Electrodes
- Electrolysis: Used in refining metals, producing gases like hydrogen and oxygen.
- Batteries: Electrodes are critical for energy storage and release in electrochemical cells.
- Corrosion Prevention: Electrodes can be used to protect metals from corrosion through cathodic protection.
Understanding these concepts is essential for grasping the chemical effects of electric current in various applications.