What is the oxidation and reduction potential of standard hydrogen electrode?

The standard electrode potential of $M^{+} / M$ in aqueous solution does not depend on

Fill in the blanks :
$1$. ...... metal is the strongest reducing agent in aqueous solution.
$2$. ...... gas is the strongest oxidizing agent.
$3$. The standard reduction potential of any electrode is measured with reference to ......

Calculate the standard cell potential $(E_{cell}^{o})$ for the following electrochemical cells:
$(i)$ $Al_{(s)}|Al_{(1M)}^{3+}||Cu_{(1M)}^{2+}|Cu_{(s)}$
$(ii)$ $Al_{(s)}|Al_{(1M)}^{3+}||Zn_{(1M)}^{2+}|Zn_{(s)}$
$(iii)$ $Al_{(s)}|Al_{(1M)}^{3+}||Ag_{(1M)}^{+}|Ag_{(s)}$
$($ Given: $E_{Al^{3+}|Al}^{o} = -1.66 \ V$,$E_{Zn^{2+}|Zn}^{o} = -0.76 \ V$,$E_{Cu^{2+}|Cu}^{o} = 0.34 \ V$,$E_{Ag^{+}|Ag}^{o} = 0.80 \ V$ $)$

Given that the standard reduction potentials for $M^{+}/M$ and $N^{+}/N$ electrodes at $298 \ K$ are $0.52 \ V$ and $0.25 \ V$ respectively. Which of the following is correct in respect of the following electrochemical cell?
$M | M^{+} || N^{+} | N$

Given $E_{Fe^{3+}|Fe}^0 = -0.036 \ V$ and $E_{Fe^{2+}|Fe}^0 = -0.439 \ V$,calculate $E^0_{cell}$ for the reaction $Fe^{3+} + e^{-} \rightarrow Fe^{2+}$.