For the reduction of NO⊖3 ion in an aqueous solution, E⊖ is +0.96 V, the values of E⊖ for some metal ions are given below:
The pair(s) of metals that is/are oxidized by NO⊖3 in aqueous solution is/are
Hg and Fe
V and Hg
Fe and V
The basic idea is pretty straightforward here. You need to see if a reaction is spontaneous or not. How do you do this? Calculate the overall E0 of the reaction. If it is +ve, then the reaction would be spontanoues. Easy enough?
You just need to check with every option since this is a multiple answer correct question.
Compare the standard reduction potential fo the given metals with that of NO⊖3 reduction.
E⊖reduction for NO⊖3 is greater than E⊖reduction of (i), (ii), and (iv).
So, NO⊖3 will be able to oxidize Fe, Hg, and V.
So pairs are as in (b), (c) and (d).