Final answer:
The Nernst Equation relates cell potential to the reaction quotient and is key in determining free energy changes and the direction of redox reactions. Equilibrium potential describes the electric potential that counterbalances an ionic gradient, leading to no net ion flux.
Step-by-step explanation:
The Nernst Equation enables the determination of cell potential under non-standard conditions. It relates the measured cell potential to the reaction quotient and is used to calculate equilibrium constants, such as solubility constants. The equation demonstrates how cell potential changes with concentration; as the reactants and products change concentration during a reaction, the cell potential changes as well.
The significance of the Nernst Equation lies in its ability to determine the direction of a spontaneous reaction and the free energy change in any redox reaction in aqueous solution. When a redox reaction is at equilibrium, the free energy change (ΔG) is zero, the reaction quotient (Q) equals the equilibrium constant (K), and there is no net transfer of electrons resulting in Ecell being zero, according to the Nernst equation.
Equilibrium potential is the electrical potential difference that precisely balances an ionic concentration gradient between two compartments or sides of a membrane, so that the net flux of the ion is zero. It is an essential concept in electrochemistry and bioelectricity, as it explains how and why ions move across membranes.