Question

Consider a voltaic cell based on the following cell reaction:

Answer 1

Answer:

$E^0_{[At_2/At^-]}=0.30V$

Explanation:

$Ni+At_{2}\rightarrow Ni^{2+}+2At^-$

Here Ni undergoes oxidation by loss of electrons, thus act as anode. At undergoes reduction by gain of electrons and thus act as cathode.

$E^0=E^0_{cathode}- E^0_{anode}$

Where both $E^0$ are standard reduction potentials.

$E^0_{[Ni^{2+}/Mg]}= -0.25V$

$E^0_{[At_2/At^-]}=?$

$E^0_{cell}=0.55V$

$E^0=E^0_{[At_2/At^-]}- E^0_{[Ni^{2+}/Mg]}$

$0.55V=E^0_{[At_2/At^-]-(-0.25V)$

$E^0_{[At_2/At^-]}=0.30V$