AIPMT - 3rd May 2015

Given below are half cell reactions :

${\mathrm{MnO}}_4^{-}+8{\mathrm{H}}^{+}+5{\mathrm{e}}^{-}\to {\mathrm{Mn}}^{2+}+4{\mathrm{H}}_2\mathrm{O}$,

${\mathrm{E}}_{{\mathrm{Mn}}^{2+}/{\mathrm{MnO}}_4^{-}}^{\mathrm{o}}=-1.510 \mathrm{V}$

$\frac{1}{2}{\mathrm{O}}_2+2{\mathrm{H}}^{+}+2{\mathrm{e}}^{-}\to {\mathrm{H}}_2\mathrm{O}$

${\mathrm{E}}_{{\mathrm{O}}_2/{\mathrm{H}}_2\mathrm{O}}^{\mathrm{o}}=+1.223 \mathrm{V}$

Will the permanganate ion, ${\mathrm{MnO}}_4^{-}$ liberate ${\mathrm{O}}_2$ from water in the presence of an acid?

At $298 \mathrm{K}$, the standard electrode potentials of ${\mathrm{Cu}}^{2+}/\mathrm{Cu}, {\mathrm{Zn}}^{2+}/\mathrm{Zn}, {\mathrm{Fe}}^{2+}/\mathrm{Fe}$ and ${\mathrm{Ag}}^{+}/\mathrm{Ag}$ are $0.34 \mathrm{V}$, $-0.76 \mathrm{V}$, $-0.44 \mathrm{V}$ and $0.80 \mathrm{V}$, respectively.

On the basis of standard electrode potential, predict which of the following reaction cannot occur?

Find the emf of the cell in which the following reaction takes place at $298 \mathrm{K}$

$\mathrm{Ni}\left(\mathrm{s}\right)+2{\mathrm{Ag}}^{+}(0.001 \mathrm{M})\to {\mathrm{Ni}}^{2+}(0.001\mathrm{M})+2\mathrm{Ag}\left(\mathrm{s}\right)$

(Given that $\mathrm{E}{°}_{\mathrm{cell}}=1.05 \mathrm{V}, \frac{2.303 \mathrm{RT}}{\mathrm{F}}=0.059$ at $298 \mathrm{K}$)

Identify the reaction from following having top position in electrochemical series according to their standard electrode potential.

In a typical fuel cell, the reactants (R) and product (P) are :-

The number of Faradays(F) required to produce $20\mathrm{g}$ of calcium from molten ${\mathrm{CaCl}}_2$ (Atomic mass of $\mathrm{Ca}=40\mathrm{g} {\mathrm{mol}}^{–1}$) is

The molar conductance of $\mathrm{NaCl}, \mathrm{HCl}$ and ${\mathrm{CH}}_3\mathrm{COONa}$ at infinite dilution are $126.45, 426.16$ and $91.0 {\mathrm{Scm}}^2{ \mathrm{mol}}^{-1}$ respectively. The molar conductance of ${\mathrm{CH}}_3\mathrm{COOH}$ at infinite dilution is. Choose the right option for your answer.

The molar conductivity of $0.007 \mathrm{M}$ acetic acid is $20 \mathrm{S}{ \mathrm{cm}}^2{ \mathrm{mol}}^{-1}.$ What is the dissociation constant of acetic acid? Choose the correct option.

$$\begin{gathered} {\mathrm{\lambda }}_{{\mathrm{H}}^{+}}^{\circ }=350 \mathrm{S} {\mathrm{cm}}^2 {\mathrm{mol}}^{-1} \\ {\mathrm{\lambda }}_{{\mathrm{CH}}_3{\mathrm{COO}}^{-}}^{\circ }=50 \mathrm{S} {\mathrm{cm}}^2 {\mathrm{mol}}^{-1} \end{gathered}$$