Applied potential

Definition

Applied potential refers to the voltage applied to an electrochemical cell or an electrode system to drive a redox reaction or facilitate the transfer of electrons. This concept is crucial in electrochemical techniques, where the applied potential influences the current response and the overall efficiency of the measurement process.

5 Must Know Facts For Your Next Test

1. The applied potential can be varied systematically during an experiment, allowing for the investigation of different redox processes and reaction mechanisms.
2. In voltammetry, the current measured is directly related to the applied potential, enabling quantitative analysis of analyte concentrations.
3. Different analytes will respond uniquely to varying applied potentials, leading to distinct current responses that can be used for identification and characterization.
4. The choice of applied potential must be carefully considered, as too high or too low values can lead to unwanted side reactions or electrode degradation.
5. Applied potential is also critical in amperometry, where the constant application of a specific voltage allows for continuous monitoring of current related to analyte concentration.

Review Questions

• How does varying the applied potential affect the current response in voltammetric techniques?
  • Varying the applied potential alters the energy available for electron transfer reactions at the electrode surface. As the potential changes, it can lead to oxidation or reduction processes, which are reflected as changes in current. By analyzing these current responses at different potentials, one can gain insights into the kinetics and thermodynamics of the redox reactions occurring in the system.
• Discuss how applied potential plays a role in determining the selectivity of an electrochemical sensor.
  • The selectivity of an electrochemical sensor is significantly influenced by the applied potential because different species will exhibit unique oxidation or reduction behaviors at specific potentials. By choosing an optimal applied potential, one can enhance the sensitivity for a particular analyte while minimizing interference from others. This selective measurement is crucial for accurate and reliable detection in complex mixtures.
• Evaluate the implications of improperly setting the applied potential on electrochemical measurements and data accuracy.
  • Improperly setting the applied potential can lead to inaccurate measurements due to either insufficient driving force for desired reactions or excessive energy causing unwanted side reactions. This can result in distorted current readings, making it difficult to determine analyte concentrations accurately. Furthermore, prolonged exposure to incorrect potentials may damage electrodes, leading to long-term reliability issues in data collection and overall performance of electrochemical systems.

Related terms

Electrode: An electrical conductor used to make contact with a non-metallic part of a circuit, often involved in redox reactions within electrochemical cells.

Cyclic Voltammetry: An electrochemical technique that involves cycling the applied potential to study the redox behavior of an analyte, providing insights into its electrochemical properties.

Reduction Potential: The tendency of a chemical species to acquire electrons and thereby be reduced, measured under standard conditions and essential for understanding redox reactions.