Inorganic and Applied Chemistry

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Inorganic and Applied Chemistry

The half cell potential (   ^0 values) corresponding to the given half cell reactions are sometimes referred to as

standard reduction potentials and may be found in tables. Typically one of the half cell reactions should be

turned around as each redox reaction contains one reduction reaction and one oxidation reaction. This means

that one of the signs from the table must be turned around. Further may the half cell reaction from the table

typically be multiplied with an integer in order to make sure that the number of electrons fits the number of

consumed electrons from the overall cell reaction. These integer multiplications are associate with the

determination of the free energy of Gibb’s for a half cell reaction:

G^0 z F +^0 (6- 2)

G^0 denotes the change in standard Gibb’s energy while z denotes the number of transferred electrons for the

half cell reaction. The Faraday constant is denoted F. G is often used to determine whether or not a

rewaction runs spontaneously. The total value of G for a electrochemical reaction is determined as the sum

ofG for the two half cell reactions. If G is less than zero the reaction runs spontaneously. If G is larger

than zero energy must be added to the system in order to let the reaction take place. This we will look into in

the following example:

Electrochemistry

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