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MHT CET · Chemistry · Electrochemistry

Oxidation potential of unimoles of calomel is

  1. A \(+0.25 \mathrm{~V}\)
  2. B \(0.00 \mathrm{~V}\)
  3. C \(+0.287 \mathrm{~V}\)
  4. D \(-0.28 \mathrm{~V}\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(-0.28 \mathrm{~V}\)

Step-by-step Solution

Detailed explanation

Calomel is used as a secondary reference electrode. Since \(\mathrm{Hg}\) is less reactive than \(\mathrm{H}\), its standard reduction potential is positive. Hence, its standard oxidation potential must be negative, \(i e,-0.28 \mathrm{~V}\). [As standard reduction potential = \(-\) standard oxidation potential.]