Page 10 - Pharmaceutical Analytical Chemistry II - Pharm D Clinical- 07-PA202

Standard Electrode potential, E0

It is the electrode potential whenever the activities of reactants and

products of the half-reaction are all unity. The electrode in

question is connected as cathode and the standard hydrogen

electrode, SHE is connected as anode

Reactant/Product Activity term, A Standard state
activity
Gas [A] = partial pressure in atm,
PA p = 1 atm
Soluble substance (1 atm = 760 mm Hg)
Pure solid, [A] = activity ≈ Molar conc., M 1M
Pure liquid,
Solvent No term for A is included in
equation, represented as 1

Standard hydrogen reference electrode "SHE"

Consists of:
Metal conductor: a piece of platinum that is platinized with finely
divided platinum (platinum black).
Electrolyte solution: aqueous acid solution, 1.00 M.

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