Single Electrode Potential and Hemholtz Double Layer

• Reactions that take when a metal electrode is in contact with its own salt solution is due to a tendency called Nernst electrolytic solution tension
• In oxidation reaction, metal ions enter into electrolyte solution leaving behind electrons on electrode
• In reduction reaction, positive metal ions take electrons from electrode and gets deposited as metal on electrode
• Equilibrium is reached in the vicinity of the electrode due to electrostatic force and further transference of ion does not take place. Hence, positive charge and negative charge remain close to metal surface forming double layer called Helmholtz Electrical Double Layer
• Difference in potential due to HEDL between metal and solution is called single electrode potential
• Constant potential difference developed when metal is in ontact with its own salt solution of conc. 1M and 25C => Standard Electrode Potential of Metal