Question

Can nickel displace hydrogen from hydrochloric acid?

\[\ce{E^{\circ}_{{Ni^{2+}/{Ni}}}}\] = −0.25 V

Answer 1

The cathode reaction is:

\[\ce{2H+ + 2e- -> H2}\]; E° = 0.00 V

The anode reaction is:

\[\ce{Ni -> Ni^2+ + 2e-}\]; E° = −0.25 V

Standard electrode potential of a cell is:

\[\ce{E{^{\circ}_{cell}} = E{^{\circ}_{cathode}} - E{^{\circ}_{anode}}}\]

= 0.00 − (−0.25)

= +0.25 V

Yes, nickel can displace hydrogen from hydrochloric acid because the cell potential is positive (+0.25 V), indicating the reaction is spontaneous.