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# Electrochemistry

Electrochemistry is the study of electricity and how it relates to chemical reactions. In electrochemistry, electricity can be generated by movements of electrons from one element to another in a reaction known as redox or oxidation-reduction reaction.

• Electrochemistry Basics
Electrochemistry is the study of chemical processes that cause electrons to move. This movement of electrons is called electricity, which can be generated by movements of electrons from one element to another in a reaction known as an oxidation-reduction ("redox") reaction.
• Connection between $$E_{cell}$$, ∆G, and K
The connection between cell potential, Gibbs energy and constant equilibrium are directly related in the following multi-part equation: ΔGo=−RTlnKeq=−nFEocell
• Electrodes
• Electrolytic Cells
Voltaic cells are driven by a spontaneous chemical reaction that produces an electric current through an outside circuit. These cells are important because they are the basis for the batteries that fuel modern society. But they are not the only kind of electrochemical cell. The reverse reaction in each case is non-spontaneous and requires electrical energy to occur.
• Exemplars
• Faraday's Law
Faraday's law of electrolysis might be stated this way: the amount of substance produced at each electrode is directly proportional to the quantity of charge flowing through the cell. Of course, this is somewhat of a simplification. Substances with different oxidation/reduction changes in terms of the electrons/atom or ion will not be produced in the same molar amounts. But when those additional ratios are factored in, the law is correct in all cases.
• Nernst Equation
The Nernst Equation enables the determination of cell potential under non-standard conditions. It relates the measured cell potential to the reaction quotient and allows the accurate determination of equilibrium constants (including solubility constants).
• Nonstandard Conditions: The Nernst Equation
The standard cell potentials refer to cells in which all dissolved substances are at unit activity, which essentially means an "effective concentration" of 1 M. Similarly, any gases that take part in an electrode reaction are at an effective pressure of 1 atm. If these concentrations or pressures have other values, the cell potential will change in a manner that can be predicted from the principles you already know.
• Redox Chemistry
• Redox Potentials
• Electricity and the Waterfall Analogy
• Voltaic Cells
In redox reactions, electrons are transferred from one species to another. If the reaction is spontaneous, energy is released, which can then be used to do useful work. To harness this energy, the reaction must be split into two separate half reactions: the oxidation and reduction reactions. The reactions are put into two different containers and a wire is used to drive the electrons from one side to the other. In doing so, a Voltaic/ Galvanic Cell is created.