Which of the following metals does not liberate $\text{H}_2$ gas by reacting with $\text{HCl}$?

Standard reduction potentials for the following reactions are :
$Fe^{3+} + 3e^{-} \rightarrow Fe ; E^{\circ}_{1} = -0.036 \ V$
$Fe^{2+} + 2e^{-} \rightarrow Fe ; E^{\circ}_{2} = -0.44 \ V$
What will be the standard electrode potential for
$Fe^{3+} + e^{-} \rightarrow Fe^{2+} (in $V$)?$

What is $emf$?

According to standard electrode potential,which is the strongest reducing agent and oxidising agent?
$Al (-1.66 \ V), Cu (+0.34 \ V), Li (-3.05 \ V), Ag (+0.80 \ V)$

On the basis of the following $E^o$ values,the strongest oxidizing agent is:
$[Fe(CN)_6]^{4-} \to [Fe(CN)_6]^{3-} + e^-; E^o = -0.35 \ V$
$Fe^{2+} \to Fe^{3+} + e^-; E^o = -0.77 \ V$

What does the negative sign in the expression $E_{Zn^{2+}|Zn}^o = -0.76 \ V$ mean?