Difference between revisions of "Reference Electrode Potentials"
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{| border="2" style="width:600px; height:200px;" | {| border="2" style="width:600px; height:200px;" | ||
− | |+ '''Table 1. Potential (V) of the | + | |+ '''Table 1. Potential (V) of the Calomel Electrode at 25°C''' |
! scope="col" | Conditions | ! scope="col" | Conditions | ||
! scope="col" | vs NHE | ! scope="col" | vs NHE | ||
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'''NOTES''' | '''NOTES''' | ||
+ | :SCE, saturated calomel electrode | ||
+ | :SSCE, saturaded salt calomel electrode | ||
+ | :NCE, normal calomel electrode | ||
+ | :NHE, normal hydrogen electrode |
Revision as of 12:47, 4 August 2014
The calomel electrode is usually constructed from a platinum wire inserted into a a mixture of calomel (mercurous chloride, Hg2Cl2) and mercury with an electrolyte solution of KCl or NaCl. The relevant half equation is:
Hg2Cl2 + 2e– == 2Hgliq + 2Cl–
Conditions | vs NHE | vs SCE | LJ | Reference |
---|---|---|---|---|
Hg/Hg2Cl2, KCl (0.1M) | 0.3337 | 0.0925 | - | 1,3 |
Hg/Hg2Cl2, KCl (0.1M) | 0.336 | 0.092 | Yes | 2 |
Hg/Hg2Cl2, KCl (1M) NCE (Normal Calomel) | 0.2801 | 0.0389 | - | 1,3 |
Hg/Hg2Cl2, KCl (1M) NCE (Normal Calomel) | 0.283 | 0.039 | Yes | 2 |
Hg/Hg2Cl2, KCl (3.5M) | 0.250 | 0.006 | Yes | 2 |
Hg/Hg2Cl2, KCl (sat'd) SCE (Sat'd Calomel) | 0.2412 | 0 | - | 1,3 |
Hg/Hg2Cl2, KCl (sat'd) SCE (Sat'd Calomel) | 0.244 | 0 | Yes | 2 |
Hg/Hg2Cl2, NaCl (sat'd) | 0.2360 | -0.0052 | - | 1 |
NOTES
- SCE, saturated calomel electrode
- SSCE, saturaded salt calomel electrode
- NCE, normal calomel electrode
- NHE, normal hydrogen electrode