Search results
Results From The WOW.Com Content Network
For example, from Fe 2+ + 2 e − ⇌ Fe(s) (–0.44 V), the energy to form one neutral atom of Fe(s) from one Fe 2+ ion and two electrons is 2 × 0.44 eV = 0.88 eV, or 84 907 J/(mol e −). That value is also the standard formation energy (∆ G f °) for an Fe 2+ ion, since e − and Fe( s ) both have zero formation energy.
The equation for local ion density can be substituted into the Poisson equation under the assumptions that the work being done is only electric work, and that the concentration of salt is much higher than the concentration of ions. [4] The electric work to bring an ion of charge to a surface with potential ψ can be represented by =. [4]
[1] [2] The actual physiological potential depends on the ratio of the reduced (Red) and oxidized (Ox) forms according to the Nernst equation and the thermal voltage. When an oxidizer (Ox) accepts a number z of electrons ( e −) to be converted in its reduced form (Red), the half-reaction is expressed as: Ox + z e − → Red
The larger the value of the standard reduction potential, the easier it is for the element to be reduced (gain electrons); in other words, they are better oxidizing agents. For example, F 2 has a standard reduction potential of +2.87 V and Li + has −3.05 V: F 2 (g) + 2 e − ⇌ 2 F − = +2.87 V Li + + e − ⇌ Li (s) = −3.05 V
In short, an electric potential is the electric potential energy per unit charge. This value can be calculated in either a static (time-invariant) or a dynamic (time-varying) electric field at a specific time with the unit joules per coulomb (J⋅C −1) or volt (V). The electric potential at infinity is assumed to be zero.
The sum is taken over all ions in the solution. mol dm −3 or mol dm −3 kg −1 [N] [L] −3 [M] −1: Electrochemical potential (of component i in a mixture) ¯ ¯ = φ = local electrostatic potential (see below also) z i = valency (charge) of the ion i. J
Ionic potential is the ratio of the electrical charge (z) to the radius (r) of an ion. [1]= = As such, this ratio is a measure of the charge density at the surface of the ion; usually the denser the charge, the stronger the bond formed by the ion with ions of opposite charge.
The electrostatic energy of the ion at site r i then is the product of its charge with the potential acting at its site E e l , i = z i e V i = e 2 4 π ε 0 r 0 z i M i . {\displaystyle E_{el,i}=z_{i}eV_{i}={\frac {e^{2}}{4\pi \varepsilon _{0}r_{0}}}z_{i}M_{i}.}