Electrochemistry · JEE Main previous year questions

2004 3 questions

1. Q1792004 · 24 Apr 2004 · Shift 1

   In a hydrogen – oxygen fuel cell, combustion of hydrogen occurs to :

   1. A.generate heat
   2. B.remove adsorbed oxygen from electrode surfaces
   3. C.produce high purity water
   4. D.create potential difference between the two electrodes
   Show answer

   Answer: D

2. Q1802004 · 24 Apr 2004 · Shift 1

   Consider the following $E^{\circ }$ values $E_{F{e}^{3+}/F{e}^{2+}}^{\circ }$ = 0.77 V; $E_{S{n}^{2+}/Sn}^{\circ }$ = -0.14 V Under standard conditions the potential for the reaction $\mathrm{Sn}(\mathrm{s})+2F{\mathrm{e}}^{3+}(\mathrm{aq})\to 2F{\mathrm{e}}^{2+}(\mathrm{aq})+\mathrm{S}{\mathrm{n}}^{2+}(\mathrm{aq})$ is :

   1. A.1.68 V
   2. B.0.63 V
   3. C.0.91 V
   4. D.1.40 V
   Show answer

   Answer: C

3. Q1832004 · 24 Apr 2004 · Shift 1

   In a cell that utilises the reaction $\mathrm{Zn}(\mathrm{s})+2{\mathrm{H}}^{+}(\mathrm{aq})\to \mathrm{Z}{\mathrm{n}}^{2+}(\mathrm{aq})+{\mathrm{H}}_2(\mathrm{g})$ addition of ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_4$ to cathode compartment, will

   1. A.lower the E and shift equilibrium to the left
   2. B.increases the E and shift equilibrium to the left
   3. C.increase the E and shift equilibrium to the right
   4. D.Lower the E and shift equilibrium to the right
   Show answer

   Answer: C