The standard reduction potentials of $2 \mathrm{H}^{+} / \mathrm{H}_2, \mathrm{Cu}^{2+} / \mathrm{Cu}$, $\mathrm{Zn}^{2+} / \mathrm{Zn}$ and $\mathrm{NO}_3^{-}, \mathrm{H}^{+} / \mathrm{NO}$ are $0.0,0.34,-0.76$ and 0.97 V pespectively. Identify the correct statements from the following I. $\mathrm{H}^{+}$does not oxidize Cu to $\mathrm{Cu}^{2+}$ II. Zn reduces $\mathrm{Cn}^{2+}$ to Cu III. $\mathrm{NO}_3^{-}$oxidizes Cu to $\mathrm{Cu}^{2+}$

The greater the negative value of the reduction potential value in the electrochemical series, the greater will be the tendency to act as a reducing agent it mean it can reduce other element whose value is high. \begin{array}{ll}\mathrm{Zn}^{2+} / \mathrm{Zn} & -0.76 V \\2 \mathrm{H}^{+} / \mathrm{H}_2 & 0 V \\\mathrm{Cu}^{2+} / \mathrm{Cu} & 0.34 V \\\mathrm{NO}_3^{-} / \mathrm{H}^{+} / \mathrm{NO} & 0.97 V\end{array} Zinc acts as a good reducing agent than copper. This implies that zinc can reduce copper. $2 \mathrm{H}^{+} / \mathrm{H}_2$ cannot oxides $\mathrm{Cu} / \mathrm{Cu}^{2+}$ because it have lower reduction potential then copper. $\mathrm{NO}_3^{-}$have high reduction potential, it can oxides copper.