Page 8 - Pharmaceutical Analytical Chemistry II - Pharm D Clinical- 07-PA202

3. METAL / INSOLUBLE SALT OF METAL / ION IN COMMON WITH
SALT electrode
• Silver/silver chloride electrode:

Ag/AgCl/Cl─ Ag AgCl (sat΄d), Cl─ (x M) 

• Calomel electrode:

Hg/ Hg2Cl2/Cl─ Hg Hg2Cl2 (sat΄d), Cl─ (x M) 

What is the ? Absolute, Single

• Electrode potential

• Cell potential

• Liquid junction potential

Electrode Potential

"Half-Cell Potential"

The potential that develops at the phase boundary between
Electrode / Electrolyte solution

It is impossible to determine absolute half-cell potentials, we can

readily determine relative electrode potentials, because all

voltage-measuring devices measure only differences in potential.

Cell Potential

The difference between two half-cell potentials

Ecell = Ecathode ─ Eanode

It is potential difference that develops between the Electrodes of the cell
It is measured using high-resistance voltmeter, under open circuit
condition (Open circuit----No current is drawn from it and No reaction
occurs, the cell develops a potential "electromotive force, emf").

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