Standard Hydrogen Electrode Definition ,Construction ,Working | Determination of Electrode potential
It is used as a primary standard (reference electrode) For measuring the potential of other electrodes. It can act both as anode and cathode. Construction of SHE: 1M HCl solution Temperature= 25 C Pressure= 1 atm Electrode Potential = 0.00V SHE consists of a platinum foil, which is coated with finely powdered platinum so as to increase its surface area and rate of reaction.The platinum foil is fitted in a glass tube and suspended in 1M HCl solution, at a pressure of 1 atmosphere. The platinum Foil acts as an electrical conductor and helps to establish equilibrium b/w hydrogen gas and its ions in solution. Determination of Electrode Potential: The potential of an electrode can be measured by coupling with standard hydrogen electrode (SHE). SHE and the electrode are dipped in one Molar aqueous solution of their ions in Separate compartments. The two solutions are connected by a salt Bridge. A voltmeter is inserted in the wire to measure the current flow b/w SHE & The electrode. At anode oxidation takes place and at cathode reduction takes place.
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