Question

All electrode potentials are measured with respect to which reference electrode?

(a) hydrogen electrode

(b) platinum electrode

(c) calomel electrode

(d) hydrogen absorbed on platinum electrode

The question was asked at a job interview.

This intriguing question originated from Recording Electrodes in section Bioelectric Signal and Electrodes of Biomedical Instrumentation

Answer 1

The correct choice is (d) hydrogen absorbed on platinum electrode

The explanation is: All electrode potentials are measured with respect to a reference electrode, usually that of hydrogen absorbed on platinum black. Thus, considering potential of hydrogen absorbed on platinum electrode to be zero, other all have positive of negative potentials.