What is the standard reduction potential of $Cu^{2+} \mid Cu_{(s)}$ if the $E^{\circ}$ of the following cell is $0.46 \ V$ (in $V$)?
$Cu_{(s)} \mid Cu_{(aq)}^{2+} \parallel Ag_{(aq)}^{+} \mid Ag_{(s)}$ ; $E_{Ag^{+} / Ag}^{\circ} = 0.80 \ V$

Which of the following metals cannot displace $H_2$ from acids or $H_2O$ from its compounds?

Among $Mg$,$Cu$,$Fe$,and $Zn$,the metal that does not produce hydrogen gas in reaction with hydrochloric acid is:

If standard reduction potential $(E^{\circ})$ of $(Mg^{2+}_{(aq)} \mid Mg_{(s)})$,$(Ag^{+}_{(aq)} \mid Ag_{(s)})$,$(Zn^{2+}_{(aq)} \mid Zn_{(s)})$ and $(Cu^{2+}_{(aq)} \mid Cu_{(s)})$ are $-2.37 \ V$,$+0.79 \ V$,$-0.76 \ V$ and $+0.34 \ V$ respectively. Which of the following reaction is spontaneous?

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 ......

$K, Ca$ and $Li$ metals may be arranged in the decreasing order of their standard electrode potentials as