UPSC CDS Science Chemistry Questions Part 1

In case of a standard hydrogen electrode, electrode potential is zero only at 25 °C. The standard hydrogen electrode (abbreviated SHE), is a redox electrode which forms the basis of the thermodynamic scale of oxidation-reduction potentials. Its absolute electrode potential is estimated to be 4.44 ± 0.02 V at 25 °C, but to form a basis for comparison with all the other electrode reactions, the standard hydrogen electrode is arbitrarily assigned a potential of exactly ± 0.000 .... volt.