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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)

444 Views

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

411 Views

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 g
2.4 x 10⁵ g

1380 Views

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

1441 Views

605.
Given,
(i) Cu²⁺ + 2e^- → Cu, E^o = 0.337 V

(ii) Cu²⁺ +e^- → Cu⁺, E^o = 0.153

Electrode potential, E^o for the reaction,
Cu +e^- →Cu, will be

0.52 V

0.90 V

0.30 V

0.30 V

0.52 V

Gibb's free energy is an additive property.

ΔG^o = -nFE^o
For reaction, Cu²⁺ +2e^- → Cu;
ΔG^o = 2 x F x 0.337 ... (i)

For reaction, Cu⁺ → Cu²⁺ +e^-;
ΔG^o = +1 xF x 0.153
Adding Eqs. (i) and (ii), we get
Cu⁺ + e^- → Cu; ΔG^o = - -0.521 F
ΔG^o = - nFE^o

-0.521 F = -nFE^o
E^o = 0.52 V

1276 Views

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

345 Views

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.

350 Views

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 E_cell^o for pentane-oxygen fuel cell is

1.968 V
2.0968 V
1.0968 V
1.0968 V

1026 Views

609.

The equilibrium constant of the reaction:

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

E^o = 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:

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