Standard Hydrogen Electrode: The standard hydrogen electrode is a reference electrode used in redox reactions. It is assigned a potential of exactly 0.0 V r...
Standard Hydrogen Electrode:
The standard hydrogen electrode is a reference electrode used in redox reactions. It is assigned a potential of exactly 0.0 V relative to a standard hydrogen electrode, which is assumed to be at a potential of 1.0 V.
The standard hydrogen electrode is constructed from a platinum wire dipped into a solution of hydrogen ions (H+) at a constant potential. The platinum wire is inert, while the hydrogen ions have a net charge of -1.
Nernst Equation:
The Nernst equation is a mathematical expression that relates the potential of an electrochemical cell to the concentrations of reactants and products. The equation is:
E = E° - (RT/nF) ln Q
where:
E is the cell potential in volts
E° is the standard cell potential in volts
R is the ideal gas constant (8.314 J/mol·K)
T is the temperature in Kelvin
n is the number of moles of electrons transferred in the balanced chemical reaction
F is the Faraday constant (96,485 C/mol)
Q is the reaction quotient, calculated as the ratio of the concentrations of products to reactants
The Nernst equation shows that the cell potential is directly proportional to the potential difference between the two electrodes and inversely proportional to the concentration of reactants. This equation is a powerful tool for understanding and predicting the potential of electrochemical cells and the overall efficiency of chemical reactions