Bubbles of gas $z$ are evolved from a solution containing $x$ and $y$. If the order of reduction potential is $x > y > z$,then:

$(i)$ Copper metal dissolves in $1 \ M$ silver nitrate solution and crystals of silver metal get deposited.
$(ii)$ Silver metal does not react with $1 \ M$ zinc nitrate solution.
$(iii)$ Zinc metal dissolves in $1 \ M$ copper sulphate solution and copper metal gets deposited.
Hence,the order of decreasing strength of the three metals as reducing agents will be:

The standard reduction potential at $298 \ K$ for the following half-cell reactions is given as:
$Zn^{2+}_{(aq)} + 2e^{-} \rightarrow Zn_{(s)} ; \quad E^{\circ} = -0.762 \ V$
$Cr^{3+}_{(aq)} + 3e^{-} \rightarrow Cr_{(s)} ; \quad E^{\circ} = -0.740 \ V$
$2H^{+}_{(aq)} + 2e^{-} \rightarrow H_{2(g)} ; \quad E^{\circ} = 0.0 \ V$
$F_{2(g)} + 2e^{-} \rightarrow 2F^{-}_{(aq)} ; \quad E^{\circ} = 2.87 \ V$
Which of the following is the strongest reducing agent?

The oxidation potentials of $Zn, Cu, Ag, H_2$ and $Ni$ are $0.76, -0.34, -0.80, 0$ and $0.25 \ V$ respectively. Which reaction provides the maximum voltage?

The standard electrode potential $(E^\circ)$ for the half-cell reaction $Fe^{3+} + e^- \rightarrow Fe^{2+}$ at $298 K$ is (Given: $E^\circ(Fe^{3+}/Fe) = -0.04 V$ and $E^\circ(Fe^{2+}/Fe) = -0.44 V$ at $298 K$)

The standard reduction potentials of $4$ elements are given below. Which of the following will be the most suitable reducing agent?
$I = -3.04 \ V$
$II = -1.90 \ V$
$III = 0 \ V$
$IV = 1.90 \ V$