For which of these oxidation/reduction pairs will the reduction potential vary with pH?
I `AmO_(2)^(2+)//AmO_(2)^(+)` II. `AmO_(2)^(2+)//Am^(4+)` III `Am^(4+) // Am^(2+)`

Options

A. I only
B. II only
C. I and II only
D. I, II only III

Answer

B

Explanation

`4H^(+) + AmO_(2)^(2+) + 2e^(-) rarr Am^(4+) + 2H_(2)O`
It includes `H^(+)` ions, hence the electrode potential depends on pH