Explain the standard electrode potential of an electrode. How is it measured?

The standard electrode potential is a measure of the tendency of a half-cell (or electrode) to either gain or lose electrons when it is in contact with a solution of its own ions at a specific temperature. It is also the potential difference between the half-cell and the standard hydrogen electrode, which is assigned a potential of 0.00 volts (V) at all temperatures.

The standard electrode potential plays a crucial role in redox reactions, serving as a tool to predict the direction of electron flow and the spontaneity of a reaction. A higher standard electrode potential means a higher tendency for the electrode to accept electrons from the other half-cell, acting as the oxidizing agent. Conversely, a lower standard electrode potential indicates a higher tendency for the electrode to give away electrons to the other half-cell, acting as the reducing agent.

The Nernst equation is used to determine the electrode potential of an electrode depending on the concentrations of the ions involved in the redox reaction. The equation is given by: E = E° - (RT / nF) × lnQ Where: - E is the electrode potential - E° is the standard electrode potential - R is the gas constant (8.314 J/mol K) - T is the temperature in Kelvin - n is the number of electrons transferred in the redox reaction - F is the Faraday's constant (96,485 C/mol) - Q is the reaction quotient

To measure the standard electrode potential of an electrode, it is necessary to set up an electrochemical cell by connecting the electrode to a standard hydrogen electrode. The following steps describe the process: 1. Set up the standard hydrogen electrode: The standard hydrogen electrode is composed of a platinum wire, covered with platinum black, immersed in an aqueous solution containing a 1M concentration of hydrogen ions (H⁺) and connected to a volt meter. A stream of hydrogen gas is bubbled through the solution at a pressure of 1 atm and a temperature of 298 K (25°C). 2. Connect the electrode of interest: The electrode whose standard electrode potential is to be measured is connected to the standard hydrogen electrode through a salt bridge or a porous disk. 3. Measure the cell potential: The cell potential, or the potential difference between the two electrodes, is measured using the voltmeter. The potential difference should be positive for the reaction to be spontaneous. 4. Calculate the standard electrode potential: The standard electrode potential of the electrode can now be calculated using the Nernst equation: E = E° - (RT / nF) × lnQ Assuming the reaction conditions to be standard (1M solution and 298 K temperature), the Nernst equation simplifies to E = E°. Since the standard hydrogen electrode potential is 0.00 V, the cell potential equals the standard electrode potential of the electrode: E° = cell potential Now, you have successfully explained the standard electrode potential and its measurement method.