The standard reduction potentials at 298 K for the following half cells are given below: NO_3^-+4 H^++3 e^- → NO ( g )+2 H_2 O, E^θ=0.97 V; V^2+( aq…

The standard reduction potentials at $\displaystyle 298$ K for the following half cells are given below: $$\begin{array}{ll} \mathrm{NO}_3^{-}+4 \mathrm{H}^{+}+3 \mathrm{e}^{-} \rightarrow \mathrm{NO}(\mathrm{~g})+2 \mathrm{H}_2 \mathrm{O} & \mathrm{E}^\theta=0.97 \mathrm{~V} \\ \mathrm{~V}^{2+}(\mathrm{aq})+2 \mathrm{e}^{-} \rightarrow \mathrm{V} & \mathrm{E}^\theta=-1.19 \mathrm{~V} \\ \mathrm{Fe}^{3+}(\mathrm{aq})+3 \mathrm{e}^{-} \rightarrow \mathrm{Fe} & \mathrm{E}^\theta=-0.04 \mathrm{~V} \\ \mathrm{Ag}^{+}(\mathrm{aq})+\mathrm{e}^{-} \rightarrow \mathrm{Ag}(\mathrm{~s}) & \mathrm{E}^\theta=0.80 \mathrm{~V} \\ \mathrm{Au}^{3+}(\mathrm{aq})+3 \mathrm{e}^{-} \rightarrow \mathrm{Au}(\mathrm{~s}) & \mathrm{E}^\theta=1.40 \mathrm{~V} \end{array} $$ The number of metal(s) which will be oxidized by $\displaystyle \mathrm{NO}_3^{-}$in aqueous solution is $\displaystyle \_\_\_\_$.