Consider the following electrochemical cell notation: M(s) / M2+ (aq)// H+ (aq)/ H2(g). The value of the electrode potential is positive when?
Answer Details
The electrode potential is positive when electrons flow from the metal electrode, M(s), to the hydrogen electrode, H2(g). The electrochemical cell notation M(s) / M2+ (aq) // H+ (aq) / H2(g) represents a cell with a metal electrode M(s) in contact with a solution containing M2+ ions and a hydrogen electrode in contact with a solution containing H+ ions. The double vertical lines (||) represent the salt bridge or porous membrane used to separate the two solutions while allowing the flow of ions to maintain electrical neutrality. The electrode potential of a cell is a measure of the tendency of electrons to flow from one electrode to another. In this case, the electrode potential is positive when electrons flow from the metal electrode, M(s), to the hydrogen electrode, H2(g). This means that the metal electrode has a higher tendency to lose electrons and become oxidized, while the hydrogen electrode has a lower tendency to gain electrons and become reduced. When electrons flow from the metal electrode to the hydrogen electrode, a current is generated and the flow of electrons is accompanied by the flow of positive ions from the metal solution to the hydrogen solution, and vice versa. The flow of current is related to the electrode potential and the resistance of the circuit, and can be used to do work such as powering a light bulb or charging a battery. In conclusion, the electrode potential is positive when electrons flow from the metal electrode, M(s), to the hydrogen electrode, H2(g), in an electrochemical cell. This is because the metal electrode has a higher tendency to lose electrons and become oxidized, while the hydrogen electrode has a lower tendency to gain electrons and become reduced.