Electrochemistry

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Electrochemistry is a field of chemistry that usually involves redox reaction that occur in between a species in a solution and species on a metal surface.

redox reactions in which a species is oxided while another is reduced.

Reduction Potential

Different species have tendencies to be reduced or oxidized. A standard reduction potential table is a tabulation of the electric potential of half reactions involving the reduction of certain species measured at standard conditions (298.15K, 1 atm, 1M concentration in aqueous solution or mercury amalgam).

Table 1: Reduction potential of common half reactions.

TABLE****

The Nernst Equation

The Nernst Equation can take many forms. Two common forms are

$E<sup>cell<sup>=E<sup>o<sup><sub>cell<sub>FromGibb'sfreeenergyequationweseethattheelectricpotentialisrelatedtotheGibb'sfreeenergy<math>G=-nFE$

The higher the difference in reduction potential between the species the more favourable the reaction will be.

The solution

Galvanic Cells

The is one of the most basic types of

Two half cells reactions are requir

For example, a copper and zinc reaction. If we look up each of their standard reduction potentials, we see that the reduction potential is -0.76 for zinc and +0.34 for copper. The more positive the reduction potential, the stronger the tendency

The following is a short hand of this galvanic cell.

Standard Electrodes

Standard hydrogen electrode, Ag/AgCl electrodes, and Calcium electrodes are common electrodes used for determining the solution potential of a solution, and in turn the concentration of a solution can be determined using the Nernst equation.

Experiment in Chemistry 123 that relates to Electrochemistry

Experiment # of the Chemistry 123, involves the use of

Applications

• Ore refinement is an application of electrochemistry. From the Nernst equation, we can see that controlling the electropotential of a system, one can control the concentrations at which processes occur. There is a company in Toronto, Trek, that specializes in the
• An alternate source of energy is the electrochemical fuel cell. The fuel cell utilizes the concepts of electrochemistry