Electrochemistry · JEE Main previous year questions

2014 4 questions

1. Q682014 · 6 Apr 2014 · Shift 1

   Resistance of $0.2\mathrm{M}$ solution of an electrolyte is $50\Omega$. The specific conductance of the solution is $1.4\mathrm{S}{\mathrm{m}}^{-1}$. The resistance of $0.5\mathrm{M}$ solution of the same electrolyte is $280\Omega$. The molar conductivity of $0.5\mathrm{M}$ solution of the electrolyte in $\mathrm{S}{\mathrm{m}}^2\mathrm{mo}{\mathrm{l}}^{-1}$ is :

   1. A.$5\times 10^3$
   2. B.$5\times 10^2$
   3. C.$5\times 10^{-4}$
   4. D.$5\times 10^{-3}$
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   Answer: C

2. Q692014 · 6 Apr 2014 · Shift 1

   Given below are the half-cell reactions: $\mathrm{M}{\mathrm{n}}^{2+}+2{\mathrm{e}}^{-}\to \mathrm{Mn};{\mathrm{E}}^0=-1.18\mathrm{V}$ $2(\mathrm{M}{\mathrm{n}}^{3+}+{\mathrm{e}}^{-}\to \mathrm{M}{\mathrm{n}}^{2+});{\mathrm{E}}^0=+1.51\mathrm{V}$ The ${\mathrm{E}}^0$ for $3\mathrm{M}{\mathrm{n}}^{2+}\to \mathrm{Mn}+2M{\mathrm{n}}^{3+}$ will be :

   1. A.$-0.33\mathrm{V}$; the reaction will not occur
   2. B.$-0.33\mathrm{V}$; the reaction will occur
   3. C.$-2.69\mathrm{V}$; the reaction will not occur
   4. D.$-2.69\mathrm{V}$; the reaction will occur
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   Answer: C

3. Q702014 · 6 Apr 2014 · Shift 1

   The equivalent conductance of $\mathrm{NaCl}$ at concentration $\mathrm{C}$ and at infinite dilution are ${\lambda }_C$ and ${\lambda }_{\infty }$, respectively. The correct relationship between ${\lambda }_C$ and ${\lambda }_{\infty }$ is given as: (where the constant $\mathrm{B}$ is positive)

   1. A.${\lambda }_C={\lambda }_{\infty }+(B)C$
   2. B.${\lambda }_C={\lambda }_{\infty }-(B)C$
   3. C.${\lambda }_C={\lambda }_{\infty }-(B)\sqrt{C}$
   4. D.${\lambda }_C={\lambda }_{\infty }+(B)\sqrt{C}$
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   Answer: C

4. Q882014 · 6 Apr 2014 · Shift 1

   The metal that cannot be obtained by electrolysis of an aqueous solution of its salts is :

   1. A.Cu
   2. B.Cr
   3. C.Ag
   4. D.Ca
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   Answer: D