What is the standard electrode potential $(E^o)$ for the electrode represented by $Pt, O_2(1 \, atm) | 2H^+(1 \, M)$?

Determine true $(T)$ and false $(F)$ for the following statements:
$(i)$ Always $E_{cell}^o = E_{cell}$
$(ii)$ In standard conditions,$E_{cell}^o = E_{cell}$
$(iii)$ $E_{cell}^o = E_{cell}$ is reached when the cell attains equilibrium.
$(iv)$ $E_{cell}^o = -\frac{\Delta_r G^o}{nF}$

For the given reactions:
$Sn^{2+} + 2e^{-} \rightarrow Sn$
$Sn^{4+} + 4e^{-} \rightarrow Sn$
The electrode potentials are $E^{\circ}_{Sn^{2+}/Sn} = -0.140 \ V$ and $E^{\circ}_{Sn^{4+}/Sn} = 0.010 \ V$. The magnitude of standard electrode potential for $Sn^{4+}/Sn^{2+}$,i.e.,$E^{\circ}_{Sn^{4+}/Sn^{2+}}$,is $..... \times 10^{-2} \ V$. (Nearest integer)

Which of the following reactions will be spontaneous in an electrochemical cell constructed from the given standard electrode potentials: $E_{Cl_2 \mid 2Cl^-}^0 = 1.36 \ V$ and $E_{Br_2 \mid 2Br^-}^0 = 1.09 \ V$?

What is standard electrode potential?

If $E^{0}_{Ag^{+} | Ag} = 0.80\, V$ and $E^{0}_{Cu^{2+} | Cu} = 0.34\, V$,then the standard cell potential of the cell formed by these electrodes is ........... $V$.