For the reduction of NO−3 ion in an aqueous solution, Eo is +0.96 V. Values of Eo for some metal ions are given below.
V2+ (aq)+2e−→V E0=−1.19 V
Fe3+ (aq)+3e−→Fe E0=−0.04 V
Au3+ (aq)+3e−→Au E0=+1.40 V
Hg2+ (aq)+2e−→Hg E0=+0.86 V
The pair(s) of metals that is (are) oxidised by NO−3 in aqueous solution is (are)