The correct option is B 2.49V.
Given reactions are:
Y3++3e−→Y: Eo=0.22V
Z→Z3++3e−: Eo=2.27V
We know that,
Ecell=Ecathode−Eanode
Here,
Ecathode=0.22V
Eanode=−2.27V, because initially oxidation potential is given, so to get reduction potential sign is changed.
So, putting the values,
Ecell=0.22−(−2.27)=2.49V.