Question

If the standard hydrogen electrode is used as the reduction electrode, then the emf is given by __________

(a) Ered = -E^o + (5/n) log10 [H^+]

(b) Ered = -E^o – (0.0591/n) log10 [H^+]

(c) Ered = E^o + (0.0591/n) log10 [H^+]

(d) Ered = -E^o + (0.0591/n) log10 [H^+]

This question was posed to me during an online exam.

This intriguing question originated from Types of Fuel Cells in section Electro Chemical Cells and Corrosion of Applied Chemistry

Answer 1

The correct choice is (d) Ered = -E^o + (0.0591/n) log10 [H^+]

The explanation: If the standard hydrogen electrode is used as the reduction electrode, then the emf can be given by Ered = -E^o + (0.0591/n) log10 [H^+] that is Ered = – EOX.