If the standard $emf$ of the cell $Zn_{(s)} | Zn_{(1 \ M)}^{+2} || Ag_{(1 \ M)}^{+1} | Ag_{(s)}$ is $1.55 \ V$, what is the electrical work done under standard conditions (in $kJ$)?

The standard reduction potentials at $298 \ K$ for the following half-cells are given below:
$Cr_2O_7^{2-} + 14H^+ + 6e^- \rightarrow 2Cr^{3+} + 7H_2O$,$E^{\circ} = 1.33 \ V$
$Fe^{3+} + 3e^- \rightarrow Fe$,$E^{\circ} = -0.04 \ V$
$Ni^{2+} + 2e^- \rightarrow Ni$,$E^{\circ} = -0.25 \ V$
$Ag^+ + e^- \rightarrow Ag$,$E^{\circ} = 0.80 \ V$
$Au^{3+} + 3e^- \rightarrow Au$,$E^{\circ} = 1.40 \ V$
Consider the given electrochemical reactions. The number of metal$(s)$ which will be oxidized by $Cr_2O_7^{2-}$ in aqueous solution is $.....$

The equilibrium constant for the reaction $Zn_{(s)} + Sn^{2+}_{(aq)} \rightleftharpoons Zn^{2+}_{(aq)} + Sn_{(s)}$ is $1 \times 10^{20}$ at $298 \ K$. The magnitude of standard electrode potential of $Sn/Sn^{2+}$ if $E_{Zn^{2+}/Zn}^0 = -0.76 \ V$ is $............ \times 10^{-2} \ V$. (Nearest integer)
Given : $\frac{2.303 \ RT}{F} = 0.059 \ V$

Which of the following solutions cannot be used in a salt bridge?

Given that
$E^o_{Ni^{2+} | Ni} = -0.25 \ V$
$E^o_{Cu^{2+} | Cu} = 0.34 \ V$
$E^o_{Ag^{+} | Ag} = 0.80 \ V$
$E^o_{Zn^{2+} | Zn} = -0.76 \ V$
Which of the following reactions under standard condition will not take place in the specified direction?

The standard cell potential $(E_{\text{cell}}^{\ominus})$ of a fuel cell based on the oxidation of methanol in air that has been used to power television relay station is measured as $1.21 \ V$. The standard half-cell reduction potential for $O_2$ $(E_{O_2 / H_2 O}^0)$ is $1.229 \ V$. Choose the correct statement: