Electrochemistry Basics

Electrochemistry Basics

• Electrochemistry is the study of the relationship between chemical reactions and electricity.
• It involves the transfer of electrons between atoms or molecules, resulting in a chemical change.
• Electrochemical reactions occur at the interface between an electrode and an electrolyte.

Electrochemical Cells

• An electrochemical cell is a device that generates a potential difference between two electrodes.
• There are two types of electrochemical cells:
  • Galvanic cells (voltaic cells): Spontaneous reactions that generate electricity, e.g. batteries.
  • Electrolytic cells: Non-spontaneous reactions that require an external power source, e.g. electrolysis of water.

Electrodes

• An electrode is a material that facilitates the transfer of electrons between the electrolyte and the external circuit.
• There are two types of electrodes:
  • Anode: The electrode where oxidation occurs, i.e. electrons are lost.
  • Cathode: The electrode where reduction occurs, i.e. electrons are gained.

Electrolytes

• An electrolyte is a substance that conducts electricity through the movement of ions.
• Electrolytes can be strong or weak, depending on their ability to dissociate into ions.
• Examples of electrolytes include acids, bases, and salts.

Electrochemical Reactions

• Oxidation: The loss of one or more electrons by an atom or molecule.
• Reduction: The gain of one or more electrons by an atom or molecule.
• Redox reaction: A reaction that involves both oxidation and reduction.

Key Concepts

• Electrochemical potential: The potential difference between an electrode and the electrolyte.
• Standard electrode potential: The potential of an electrode at standard conditions (1M, 1 atm, 25°C).
• Nernst equation: A mathematical equation that relates the electrode potential to the concentrations of the reactants and products.

Applications of Electrochemistry

• Batteries and fuel cells
• Electroplating and electrochemical synthesis
• Corrosion protection and prevention
• Electrochemical sensors and biosensors