Electro chemistry practice · Mixed difficulty

The specific conductivity of 0.1 N KCl solution is 0.0129 ${\Omega ^{ - 1}}\mathrm{c}{\mathrm{m}^{ - 1}}$ . The resistance of the solution in the cell 100Ω. The cell constant of the cell will be

Which of the following metal has the highest conductivity at room temperature ?

For the cell reaction

${Pb}+{Sn}^{2+} \rightarrow {Pb}^{2+}+{Sn}$

Given that, ${Pb} \rightarrow {Pb}^{2+}, {E}^{\circ}=0.13 \mathrm{~V}$

${Sn}^{2+}+2 {e}^{-} \rightarrow {Sn} ; {E}^{\circ}=-0.14 \mathrm{~V}$

What would be the ratio of cation concentration for which ${E}=0?$

Assertion : Galvanised iron does not rust.

Reason : Zinc has a more negative electrode potential than iron.

Calculate the time required to deposite $2 \times 10^{-3} \mathrm{~cm}$ thick layer of silver (density $1.05 \mathrm{~g} \mathrm{~cm}^{-3}$ ) on the surface of area $100 \mathrm{~cm}^{-3}$ by passing a current of $10 \mathrm{~A}$ through silver nitrate solution?

The cell constant of a given cell is $0.47 {~cm}^{-1}$. Theresistance of a solution placed in this cell is measured to be $31.6 \, {ohm}$. The conductivity of the solution (in ${S} {cm}^{-1}$ where ${S}$ has usual meaning) is

In metallic conductor the current is conducted by flow of

Which substance is obtained in the solution on electrolysis of aqueous $\mathrm{CuS}{\mathrm{O}_4}$ solution using graphite electrodes?

For the reaction $2F{e^{3 + }} + Fe \to 3F{e^{2 + }},\,E^\circ = 1.21\,V,$ hence

The charge present on $42 \mathrm{~g}$ of nitride ions in coulomb is

Identify the factor from the following that does not
affect electrolytic conductance of a solution.

Number of moles of $\mathrm{MnO}_4^{-}$ getting reduced to $\mathrm{MnO}_2$ under neutral condition by $4.517 \times 10^{24}$ electrons is:

250 mL of a waste solution obtained from the workshop of a goldsmith contains $0.1\,M\,AgN{O_3}$ and $0.1\,M\,AgCl.$ The solution was electrolyzed at 2 V by passing a current of 1 A for 15 minutes. The metal/metals electro deposited will be:
$\left( {E_{A{g^ + }/Ag}^0 = 0.80\,V,E_{A{u^ + }/Au}^0\, = 1.69\,V} \right)$

The cell reaction is spontaneous, when

The resistance of a conductivity cell was found to be $700 \Omega$ with $0.01 \mathrm{~M} \mathrm{~KCl}$ and $800 \Omega$ with $0.01 \mathrm{~M} \mathrm{~AgNO}_3$.

Molar conductance of $0.01 \mathrm{~M} \mathrm{~KCl}=150 \mathrm{~ohm}^{-1} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$.

Thus, molar conductance of $\mathrm{AgNO}_3$ is

The molar conductivity of $\mathrm{HCl},\mathrm{NaCl}$ and $\mathrm{C}{\mathrm{H}_3}\mathrm{COONa}$ are 425, 188, 96 $S{\kern 1pt} \mathrm{c}{\mathrm{m}^2}{\kern 1pt}{\kern 1pt}\mathrm{mo}{\mathrm{l}^{ - 1}}$ at 298 K. The molar conductivity of $\mathrm{C}{\mathrm{H}_3}\mathrm{COOH}$ at the same temperature is …. $S{\kern 1pt}{\kern 1pt}\mathrm{c}{\mathrm{m}^2}{\kern 1pt}{\kern 1pt}\mathrm{mo}{\mathrm{l}^{ - 1}}$

At $298 \mathrm{~K}$, the standard oxidation potential of $\mathrm{A}\left|\mathrm{A}^{+2}, \mathrm{~B}\right| \mathrm{B}^{+2}, \mathrm{C}\left|\mathrm{C}^{+1} , \mathrm{D}\right| \mathrm{D}^{+3}$ are $0.28 \mathrm{~V},-0.56 \mathrm{~V}$, $0.15 \mathrm{~V},-2.0 \mathrm{~V}$ respectively.

On the basis of standard oxidation potential, predict which of the following reaction can not occur:

Reduction potential of hydrogen electrode at ${pH}$ of 3 and ${p}_{{H}_2}=1 {~atm}$ is

Which of the following is correct?

Equilibrium constant for the following redox reaction at $25^{\circ} \mathrm{C}$ is

$\mathrm{Zn}^{2+}(\mathrm{aq})+\mathrm{Mg}(\mathrm{s}) \longrightarrow \mathrm{Zn}(\mathrm{s})+\mathrm{Mg}^{2+}(\mathrm{aq})$

$\left(\text { Given } \mathrm{E}_{\mathrm{Zn}^{2+} / \mathrm{Zn}}^0=-0.76 \mathrm{~V}, \mathrm{E}_{\mathrm{Mg}^{2+} / \mathrm{Mg}}^0=-2.36 \mathrm{~V}\right)$

The standard H electrode is written as :

The molar conductivities of KCl, NaCl and $\mathrm{KN}{\mathrm{O}_3}$ are 152, 128 and 111 $S{\kern 1pt} {\kern 1pt} c{m^2}{\kern 1pt} mo{l^{( - 1)}}$ respectively. What is the molar conductivity of $\mathrm{NaN}{\mathrm{O}_3}$ ?

$\mathrm{KCl}\left( {aq} \right)$ cannot be used as a salt bridge for the cell $\mathrm{Cu}\left( s \right)\left| {\mathrm{CuS}{\mathrm{O}_4}\left( {aq} \right)} \right|\left| {\mathrm{AgN}{\mathrm{O}_3}\left( {aq} \right)} \right|\mathrm{Ag}\left( s \right)$ because :

The molar conductivity at infinite dilution of $\mathrm{AgN}{\mathrm{O}_3},\mathrm{NaCl}$ and $\mathrm{NaN}{\mathrm{O}_3}$ are 116.5, 110.3 and 105.2 ${\rm{mho{\kern 1pt} {\kern 1pt} c}}{\mathrm{m}^2}{\kern 1pt} {\kern 1pt} \mathrm{mo}{\mathrm{l}^{ - 1}}$ respectively. The molar conductivity of AgCl is :

Given the limiting molar conductivity as

$\Lambda _\mathrm{m}^0\left( {\mathrm{HCl}} \right) = 425.9{\kern 1pt} {\kern 1pt} {\Omega ^{ - 1}}{\kern 1pt} \mathrm{c}{\mathrm{m}^2}{\kern 1pt} \mathrm{mo}{\mathrm{l}^{ - 1}}$

$\Lambda _\mathrm{m}^0\left( {\mathrm{NaCl}} \right) = 126.4{\kern 1pt} {\kern 1pt} {\Omega ^{ - 1}}{\kern 1pt} \mathrm{c}{\mathrm{m}^2}{\kern 1pt} \mathrm{mo}{\mathrm{l}^{ - 1}}$

$\Lambda _\mathrm{m}^0\left( {\mathrm{C}{\mathrm{H}_3}\mathrm{COONa}} \right) = 91{\kern 1pt} {\kern 1pt} {\Omega ^{ - 1}}{\kern 1pt} \mathrm{c}{\mathrm{m}^2}{\kern 1pt} \mathrm{mo}{\mathrm{l}^{ - 1}}$

The molar conductivity , at infinite dilution, of acetic acid ($\mathrm{in}{\kern 1pt} {\kern 1pt} {\kern 1pt} {\Omega ^{ - 1}}{\kern 1pt} \mathrm{c}{\mathrm{m}^2}{\kern 1pt} \mathrm{mo}{\mathrm{l}^{ - 1}}$) will be

Electrolysis of ${H}_2 {SO}_4$ (conc.) gives the following product at anode

Assertion: Molar conductance of $0.1 \mathrm{~M} \mathrm{~NH}_4 \mathrm{OH}$ solution is less than that of $0.001 \mathrm{~M} \mathrm{~NH}_4 \mathrm{OH}$ solution.

Reason: Dilution increases the degree of ionization of $\mathrm{NH}_4 \mathrm{OH}$.

The emf of the cell $\mathrm{Zn}\left| {\mathrm{Z}{\mathrm{n}^{2 + }}\left( {0.01\mathrm{M}} \right)} \right|\left| {\mathrm{F}{\mathrm{e}^{2 + }}\left( {0.001\mathrm{M}} \right)} \right|\mathrm{Fe}$ at 298 K is 0.2905. The value of equilibrium constant for the cell reaction is

Given the limiting molar conductivity as

$\Lambda _\mathrm{m}^0\left( {\mathrm{HCl}} \right) = 425.9{\kern 1pt} {\kern 1pt} {\Omega ^{ - 1}}{\kern 1pt} \mathrm{c}{\mathrm{m}^2}{\kern 1pt} \mathrm{mo}{\mathrm{l}^{ - 1}}$

$\Lambda _\mathrm{m}^0\left( {\mathrm{NaCl}} \right) = 126.4{\kern 1pt} {\kern 1pt} {\Omega ^{ - 1}}{\kern 1pt} \mathrm{c}{\mathrm{m}^2}{\kern 1pt} \mathrm{mo}{\mathrm{l}^{ - 1}}$

$\Lambda _\mathrm{m}^0\left( {\mathrm{C}{\mathrm{H}_3}\mathrm{COONa}} \right) = 91{\kern 1pt} {\kern 1pt} {\Omega ^{ - 1}}{\kern 1pt} \mathrm{c}{\mathrm{m}^2}{\kern 1pt} \mathrm{mo}{\mathrm{l}^{ - 1}}$

The molar conductivity , at infinite dilution, of acetic acid ($\mathrm{in}{\kern 1pt} {\kern 1pt} {\kern 1pt} {\Omega ^{ - 1}}{\kern 1pt} \mathrm{c}{\mathrm{m}^2}{\kern 1pt} \mathrm{mo}{\mathrm{l}^{ - 1}}$) will be

The standard reduction potentials for $\mathrm{Z}{\mathrm{n}^{2 + }}/\mathrm{Zn},\mathrm{N}{\mathrm{i}^{2 + }}/\mathrm{Ni}$ and $\mathrm{F}{\mathrm{e}^{2 + }}/\mathrm{Fe}$ are $- 0.76, - 0.23$ and$- 0.44\mathrm{V}$ respectively. The reaction$X + {Y^{2 + }} \to {X^{2 + }} + Y$ will be spontaneous when :