[mystreet123]

Why are cell potentials the same for reactions with same overal equation?

e.g. hydrogen-oxygen fuel cell in acidic and alkaline conditions

[Borek]

Why are cell potentials the same for reactions with same overal equation?

In general they are not.

[mystreet123]

Why are cell potentials the same for reactions with same overal equation?

In general they are not.

But one question from the past paper says so

[mjc123]

What happens to the individual electrode potentials on going from acid to alkaline solution? (Check them here: https://en.wikipedia.org/wiki/Standard_electrode_potential_(data_page))
So what happens to the cell potential?
Note that when you combine the half-cell equations, the H⁺ or OH^- cancels out, so the overall reaction is the same.
But it isn't always this simple. For example, some metals give Mⁿ⁺(aq) in acid solution, but form insoluble oxides or hydroxides in alkaline conditions, so the reaction isn't the same.