Calculate the $emf$ of the cell $Cu_{(s)} | Cu^{2+}_{(aq)} || Ag^+_{(aq)} | Ag_{(s)}$. Given: $E^0_{Cu^{2+}/Cu} = +0.34 \ V$,$E^0_{Ag^+/Ag} = +0.80 \ V$.

When $E^o_{Ag^{+}/Ag} = 0.8 \ V$ and $E^o_{Zn^{2+}/Zn} = -0.76 \ V$,which of the following is correct?

Which of the following has the highest electrode potential?

$FeO_4^{2-}$ $\xrightarrow{2.0 \ V} Fe^{3+}$ $\xrightarrow{0.8 \ V} Fe^{2+}$ $\xrightarrow{-0.44 \ V} Fe^0$
In the above diagram,the standard electrode potentials are given in volts. The value of $E_{FeO_4^{2-}/Fe^{2+}}^{\Theta}$ is: (in $V$)

$E^o$ values of $Mg^{2+}/Mg$,$Zn^{2+}/Zn$ and $Fe^{2+}/Fe$ are $-2.37 \ V$,$-0.76 \ V$ and $-0.44 \ V$ respectively. Which of the following statements is correct?

The standard electrode potentials $(E^{0}_{Red})$ of four elements $A, B, C,$ and $D$ are $-3.05 \ V, -1.66 \ V, -0.40 \ V,$ and $0.80 \ V$ respectively. Which of the following is the most reactive?