Consider the following relations for emf of an electrochemical c

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601.

Consider the following relations for emf of an electrochemical cell

A) Emf of cell = (oxidation potential of anode) - (reduction potential of cathode)

B) Emf of cell = (oxidation potential of anode) - ( reducation potential of cathode)

C) Emf of cell = (oxidation potential of anode)- (reduction potential of cathode)

D) Emf of cell = (oxidation potential of anode) - (oxidation potential of anode)-(oxidation potential  of cathode)

  • (C) and (A)

  • (A) and (B)

  • (C) and (D)

  • (C) and (D)


D.

(C) and (D)

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602.

For vaporisation of water at 1 atm pressure, the values of ΔH and ΔS are 40.63 kJ mol- and 108.8 JK-1 mol-1, respectively. The temperature when Gibbs energy change (ΔG) for this transformation will be zero, is

  • 273.14 K

  • 393.4 K 

  • 373.4 K 

  • 373.4 K 

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603.

Al2O3 is reduced by electrolysis at low potentials and high currents. If 4.5 x 104 An of current is passed through molten Al2O3 for 6h, what mass of aluminium is produced? (Assume 100% current efficiency, at.mass of Al = 27 g mol-1)

  • 9.0 x 103 g

  • 8.1 x 104 g

  • 2.4 x 105

  • 2.4 x 105

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604.

The equivalent conductance of M/32 solution of weak monobasic acid is 8.0 ohm-cm2 and at infinite dilution is 400 ohm-cm2. The dissociation constant of this acid is

  • 1.25 x 10-5

  • 1.25 x 10-6

  • 6.25 x 10-4

  • 6.25 x 10-4

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605.

Given, 
(i) Cu2+ + 2e- → Cu,     Eo = 0.337 V

(ii) Cu2+ +e- → Cu+, Eo = 0.153

Electrode potential, Eo for the reaction,
Cu +e- →Cu, will be 

  • 0.52 V

  • 0.90 V

  • 0.30 V

  • 0.30 V

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606.

The values of ΔH and ΔSfor the reaction, C(graphite) + CO2  → 2 CO (g) are 170 kJ and 170 JK-1 respectively. This reaction will be spontaneous at 

  • 710 K

  • 910 K

  • 1110 K

  • 1110 K

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607.

Kohlrausch's law states that at

  • finite dilution, each ion makes a definite contribution to the equivalent conductance of an electrolyte, whatever be the nature of the other ion of the electrolyte.

  • infinite dilution, each ion makes a definite contribution to the equivalent conductance of an electrolyte depending on the nature of the other ion of the electrolyte.

  • infinite dilution, each ion makes a definite contribution to the conductance of an electrolyte whatever be the nature of the other ions of the electrolyte.

  • infinite dilution, each ion makes a definite contribution to the conductance of an electrolyte whatever be the nature of the other ions of the electrolyte.

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608.

Standard free energies of formation (in kJ/mol) at 298 K are -237.2, 394.4 and -8.2 for H2O (l), CO2 (g) and pentane (g),  respectively. The value of Ecello for pentane-oxygen fuel cell is

  • 1.968 V

  • 2.0968 V

  • 1.0968 V

  • 1.0968 V

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609.

The equilibrium constant of the reaction:

Cu (s) + 2 Ag+ (aq) →  Cu2+ (aq) + 2 Ag (s);

Eo = 0.46 V at 298 K

  • 2.4 x 1010

  • 2.0 x 1010

  • 4.0 x 1010

  • 4.0 x 1010


610.

The efficiency of a fuel cell is given by:

  • fraction numerator increment straight H over denominator increment straight G end fraction
  • fraction numerator increment straight G over denominator increment straight S end fraction
  • fraction numerator increment straight G over denominator increment straight H end fraction
  • fraction numerator increment straight G over denominator increment straight H end fraction

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