Standard reduction potentials
for various half-reactions under acidic and basic conditions
are given in the linked tables on the
facing page. Remember that these potentials really are
for cells in which the electrons required on the left
side of the given half-reaction are provided by oxidizing
H2 to H+ ions, but that whenever
we use two of these half-reactions to calculate the
potential of a real cell, the hydrogen contributions
cancel. Also remember that a potential is a "pressure"
on a per electron basis,
no matter how many electrons appear in the half-reaction.
The free energy for that half-reaction coupled in a
cell with the hydrogen half-reaction can be found by
multiplying the reduction potential by -23.06 kcal times
the number of electrons involved in the half-reaction.
Example. What
are the cell voltage and free energy change in a cell
with the reaction
Which way will the reaction go spontaneously?
Solution
Now find out how to Build
cells from Half Rections
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