Redox Reactions and Electrode Processes

Hypophosphorus acid is a good reducing agent because

An iron wire is immersed in a solution containing ${\mathrm{ZnSO}}_4$ and ${\mathrm{NiSO}}_4$. When the concentration of each salt is $1\mathrm{M}$, predict which of the following reaction is likely to proceed.
Given ${\mathrm{E}}^{\mathrm{o}}\left({\mathrm{Zn}}^{+2}/\mathrm{Zn}\right)=-0.76 \mathrm{V}$
${\mathrm{E}}^{\mathrm{o}}\left({\mathrm{Fe}}^{+2}/\mathrm{Fe}\right)=-0.44 \mathrm{V}$
and ${\mathrm{E}}^{\mathrm{o}}({\mathrm{Ni}}^{+2}/\mathrm{Ni})=-0.25 \mathrm{V}$

The standard electrode potential of three metals $\mathrm{X}, \mathrm{Y}$and $\mathrm{Z}$ are $-1.2 \mathrm{V}, +0.5 \mathrm{V}$ and $-3.0 \mathrm{V}$ respectively. The reducing power of these metals will be

A gas $\mathrm{X}$ at $1 \mathrm{atm}$ is bubbled through a solution containing a mixture of $1\mathrm{M} {\mathrm{Y}}^{-}$ and $1\mathrm{M} {\mathrm{Z}}^{-}$ ions at $25°\mathrm{C}$. If the reduction potentials of $\mathrm{Z}>\mathrm{Y}>\mathrm{X}$, then

The ${\mathrm{E}}_{{\mathrm{M}}^{3+}/{\mathrm{M}}^{2+}}^{\mathrm{o}}$ values for $\mathrm{Cr},\mathrm{Mn},\mathrm{Fe}$ and $\mathrm{Co}$ are $-0.41,+1.57,+0.77$ and $+1.97\mathrm{V}$, respectively. For which one of these metals the change in oxidation state from $+2$ to $+3$ is the easiest?

Standard electrode potential of three metals $\mathrm{A},\mathrm{B}$ and $\mathrm{C}$ are $+0.5 \mathrm{V},-3.0 \mathrm{V}$ and $-1.2 \mathrm{V}$ respectively. The reducing power of these metals are

During electrolysis, the reaction at the anode is:

Which statement is true for an electrochemical cell?

The negative sign in the standard electrode potential indicates- 

Which of the following transformations can be carried out by using $HI$ as a reducing agent, under acidic conditions?

[Given : ${\mathrm{I}}_2\left(\mathrm{s}\right)\to 2{\mathrm{I}}^{-} {\mathrm{E}}^{\mathrm{o}}=0.54\mathrm{ }\mathrm{V}$ ]

(i) $\mathrm{C}{\mathrm{u}}^{+}\to \mathrm{C}\mathrm{u}\left(\mathrm{s}\right)\mathrm{ } {\mathrm{E}}^{\mathrm{o}}=0.52\mathrm{ }\mathrm{V}$

(ii) $\mathrm{C}{\mathrm{r}}^{3+}\to \mathrm{C}{\mathrm{r}}^{2+} {\mathrm{E}}^{\mathrm{o}}=-0.41\mathrm{ }\mathrm{V}$

(iii) $\mathrm{F}{\mathrm{e}}^{3+}\to \mathrm{F}{\mathrm{e}}^{2+}\mathrm{ } {\mathrm{E}}^{\mathrm{o}\mathrm{ }}=0.77\mathrm{ }\mathrm{V}$

(iv) $\mathrm{F}{\mathrm{e}}^{2+}\to \mathrm{F}\mathrm{e}\left(\mathrm{s}\right) {\mathrm{E}}^{\mathrm{o}}=-0.44\mathrm{ }\mathrm{V}$

The amount of $Ag$ (atomic mass = 108) deposited at the cathode when a current of 0.5 amp is passed through a solution of $AgN{O}_3$ for 1 hour is closest to

Which of the following metals will precipitate copper from copper sulphate solution?

The order of reactivity of $K, Mg, Au$ and $Zn$ with water is

As per study of electrochemical series, which of the following reaction is non-spontaneous?

A gas $\mathrm{X}$ at $1\mathrm{ }\mathrm{atm}$ is bubbled through a solution containing a mixture of $1\mathrm{ }\mathrm{M}\mathrm{ }{\mathrm{Y}}^{-}$ and $1\mathrm{ }\mathrm{M}\mathrm{ }{\mathrm{Z}}^{-}$ at $25 °\mathrm{C}$. If the reduction potential of $\mathrm{Z}>\mathrm{Y}>\mathrm{X}$, then

A gas $\mathrm{X}$ at $1 \mathrm{atm}$ is bubbled through a solution containing a mixture of $1 \mathrm{M} {\mathrm{y}}^{-}$ and $1 \mathrm{M} {\mathrm{z}}^{-}$ at $25\mathrm{℃}$. If the order of reduction potential is $\mathrm{z}>\mathrm{y}>\mathrm{x}$, then

Four alkali metals $A, B, C$and $D$ are having respectively standard electrode potential as $-3.05, -1.66, -0.40 \mathrm{a}\mathrm{n}\mathrm{d}\mathrm{ }0.80.$ Which one will be the most reactive?

Reduction potentials of four elements $\text{P,}\text{Q,}\text{R,}\text{S}$ is $-\text{2}\text{.90}\text{V}$, $\text{0.34}\text{V}$, $\text{1}\text{.2}\text{V}$ and $-\text{0}\text{.76}\text{V}$. The decreasing order of reducing power is

The standard electrode potential of hydrogen electrode at 1 M concentration and hydrogen gas at 1atm pressure is

${\mathrm{E}}_{\mathrm{Cu}}^{°}=0.34\mathrm{ }\mathrm{V}$ and ${\mathrm{E}}_{\mathrm{Zn}}^{°}\mathrm{ }=\mathrm{ }0.76\mathrm{ }\mathrm{V}.$ A Daniel cell contains $0.1 \mathrm{M} \mathrm{Z}\mathrm{n}\mathrm{S}{\mathrm{O}}_4$ solution and $0.01 \mathrm{M} \mathrm{C}\mathrm{u}\mathrm{S}{\mathrm{O}}_4$ solution at its electrodes. EMF of the cell is