The standard potential of the given half cell (as per convention) at 298 K is
H+(aq) + e− → ½H2(g)
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Zero
By convention, the standard hydrogen electrode is assigned a zero potential at all temperatures, so the standard potential of this half cell is zero.
NCERT (2026-27 edition):
Measurement of Electrode Potential
