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271.
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

272.

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

273.

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

274.

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

275.

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

276.

The efficiency of a fuel cell is given by:

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

277.

If $straight E to the power of straight o subscript Fe to the power of 2 plus end exponent divided by Fe end subscript space equals space minus space 0.441 space straight V space and space straight E to the power of straight o subscript Fe to the power of 3 plus end exponent divided by Fe to the power of 2 plus end exponent end subscript space equals space 0.771 space space straight V comma$ the standard emf of the reaction:

Fe + 2 Fe³⁺ →3Fe²⁺

will be:

0.330 V
1.653 V
1.212 V
1.212 V

832 Views

278.

A hypothetical electrochemical cell is shown below
A^- | A⁺ (xM)|| B⁺ (yM)|B⁺

The emf measured is +0.20 V. The cell reaction is:

A⁺ + B → A + B⁺
A⁺ + e^- → A ; B⁺ + e^- → B^-
the cell reaction cannot be predicted
the cell reaction cannot be predicted

613 Views

279.

Concentration of the Ag+ ions in a saturated solution of Ag₂C₂O₄ is 2.2 ×10^–4 mol L^–1. Solubility product

2.42 × 10^–8
2.66 × 10^–12
4.5 × 10^–11
4.5 × 10^–11

3926 Views

280.

In the electrochemical cell :
Zn|ZnSO₄(0.01M)||CuSO₄(1.0 M)|Cu, the emf of this Daniel cell is E₁. When the concentration of ZnSO₄ is changed to 1.0 M and that of CuSO₄ changed to 0.01 M, the emf changes to E₂. From the following, which one is the relationship between E₁ and E₂?
(Given, RT/F= 0.059)