Academic Experts Solutions for Chapter: Electrochemistry, Exercise 2: KVPY PROBLEMS (PREVIOUS YEARS)

The standard reduction potentials (in $\mathrm{V}$) of a few metal ion/metal electrodes are given below. The reducing strength of the metals follows the order.

$$\begin{gathered} {\mathrm{E}}_{{\mathrm{Cu}}^{+2}/\mathrm{Cu}}^0=+0.34 \\ {\mathrm{E}}_{{\mathrm{Pb}}^{+2}/\mathrm{Pb}}^0=-0.13 \\ {\mathrm{E}}_{{\mathrm{Ag}}^{+}/\mathrm{Ag}}^0=+0.80 \\ {\mathrm{E}}_{{\mathrm{Cr}}^{+3}/\mathrm{Cr}}^0=-0.74 \end{gathered}$$

The equilibrium constant of a $2$ electron redox reaction at $298 \mathrm{K}$ is $3.8\times {10}^{-3}$. The cell potential $\mathrm{E}°$ (in $\mathrm{V}$) and the free energy change $\mathrm{\Delta G}°$ (in $\mathrm{kJ} {\mathrm{mol}}^{-1}$) for this equilibrium, respectively, are

Given the standard potentials $\mathrm{E}°\left({\mathrm{Cu}}^{2+}/\mathrm{Cu}\right)$ and $\mathrm{E}°\left({\mathrm{Cu}}^{+}/\mathrm{Cu}\right)$ as $0.340 \mathrm{V}$ and $0.522 \mathrm{V}$, respectively, the value of $\mathrm{E}°\left({\mathrm{Cu}}^{2+}/{\mathrm{Cu}}^{+}\right)$ is

For electroplating, $1.5 \mathrm{amp}$ current is passed for $250 \mathrm{s}$ through $250 \mathrm{mL}$ of $0.15 \mathrm{M}$ solution of ${\mathrm{MSO}}_4$. Only $85 \%$ of the current was utilised for electrolysis. The molarity of ${\mathrm{MSO}}_4$ solution after electrolysis is closest to [Assume that the volume of the solution remained constant].

The specific conductance $\left(\mathrm{K}\right)$ of $0.02 \mathrm{M}$ aqueous acetic acid solution at $298 \mathrm{K}$ is $1.65\times {10}^{-4} \mathrm{S} {\mathrm{cm}}^{-1}$. The degree of dissociation of acetic acid is [Given: equivalent conductance at infinite dilution of ${\mathrm{H}}^{+}=349.1 {\mathrm{cm}}^2 {\mathrm{mol}}^{-1}$ and ${\mathrm{CH}}_3{\mathrm{COO}}^{-}=40.9 {\mathrm{S}}^2 {\mathrm{cm}}^2 {\mathrm{mol}}^{-1}$ ].

Among the following metals, the strongest reducing agent is:

A constant current $(0.5 \mathrm{amp})$ is passed for $1$ hour through $\left(\mathrm{i}\right)$ aqueous ${\mathrm{AgNO}}_3$, $\left(\mathrm{ii}\right)$ aqueous ${\mathrm{CuSO}}_4$ and $\left(\mathrm{iii}\right)$ molten ${\mathrm{AlF}}_3$, separately. The ratio of the mass of the metals deposited on the cathode is [${\mathrm{M}}_{\mathrm{Ag}}, {\mathrm{M}}_{\mathrm{Cu}}, {\mathrm{M}}_{\mathrm{Al}}$ are the molar masses of the respective metals]

Among the following, the plot that correctly represents the conductometric titration of $0.05 \mathrm{M} {\mathrm{H}}_2{\mathrm{SO}}_4$ with $0.1 \mathrm{M} {\mathrm{NH}}_4\mathrm{OH}$ is