Consider the following relations for emf of an electrochemical cell:

(a) emf of a cell = (Oxidation potential of the anode) – (Reduction potential of the cathode)
(b) emf of a cell = (Oxidation potential of the anode) + (Reduction potential of the cathode)
(c) emf of a cell = (Reduction potential of the anode) + (Reduction potential of the cathode)
(d) emf of a cell = (Oxidation potential of the anode) – (Oxidation potential of the cathode)


Which of the following combinations correctly represents the relation for the emf of the cell?

1. (a) and (b) 2. (c) and (d)
3. (b) and (d) 4. (c) and (a)

Subtopic:  Electrode & Electrode Potential |
 69%
Level 2: 60%+
AIPMT - 2010
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The correct expression that  represents the equivalent conductance at infinite dilution of Al2(SO4)3 is:

(Given that Al3+° and SO42-° are the equivalent conductances at infinite dilution of the respective ions)

1. Al3+° + SO42-°

2. Al3+° + SO42-°×6

3. 13Al3+° +12 SO42-°

4. 2Al3+° +3 SO42-°

Subtopic:  Conductance & Conductivity |
 64%
Level 2: 60%+
AIPMT - 2010
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Molar conductivities (°m) at infinite dilution of
NaCl, HCl, and CH3COONa are 126.4, 425.9, and 91.0 S cm2 mol–1 respectively.
 (°m)  for CH3COOH  will be: 

1. \(180.5~S~cm^2~mol^{-1}\) 2. \(290.8~S~cm^2~mol^{-1}\)
3. \(390.5~S~cm^2~mol^{-1}\) 4. \(425.5~S~cm^2~mol^{-1}\)
Subtopic:   Kohlrausch Law & Cell Constant |
 91%
Level 1: 80%+
AIPMT - 2012
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The Gibb's energy for the decomposition of \(\mathrm{A l_{2} O_{3}}\) at \(\mathrm{500~ ^\circ C}\) is as follows: 

2/3Al2O3 → 4/3Al + O2 ; ∆rG = + 960 k J mol–1

The potential difference needed for the electrolytic reduction of aluminium oxide (Al2O3) at \(\mathrm{500~ ^\circ C}\) is at least,

1. 3.0 V 

2. 2.5 V 

3. 5.0 V 

4. 4.5 V 

Subtopic:  Relation between Emf, G, Kc & pH |
 63%
Level 2: 60%+
AIPMT - 2012
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What is the mass of silver deposited when the charge passed is doubled, if a charge of \(10^5\) coulomb deposits 1 g of Ag?

1. 1 gm 2. 2 gm
3. 3 gm 4. 4 gm
Subtopic:  Faraday’s Law of Electrolysis |
 89%
Level 1: 80%+
AIPMT - 1998
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The concentration of ZnCl2 solution will change when it is placed in a container which is made of:

1. Al 2. Cu
3. Ag 4. None
Subtopic:  Electrochemical Series |
 72%
Level 2: 60%+
AIPMT - 1998
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Which of the following quantities does the change in Gibbs free energy (ΔG) depend upon, for the electrochemical cell reaction: \(Cu^{2+}(C_{1}) + Zn \to Cu + Zn^{2+}(C_{2})\)

\(1. \ ln (C_{1}+C_{2})\)
2. \(ln (\frac{C_{2}}{C_{1}})\)
\(3. \ ln C_{2}\)
\(4. \ lnC_{1}\)

Subtopic:  Relation between Emf, G, Kc & pH |
 93%
Level 1: 80%+
AIPMT - 1998
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4.5 g of aluminium (at. mass = 27 amu) is deposited at cathode from Al3+ solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from H+ ions in solution by the same quantity of electric charge will be:

1. 44.8 L 2. 11.2 L
3. 22.4 L 4. 5.6 L
Subtopic:  Faraday’s Law of Electrolysis |
 56%
Level 3: 35%-60%
AIPMT - 2005
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For the disproportionation of copper:

2Cu+ → C u2+ + C u, E° is:
(Given E° for Cu+2/Cu is 0.34 V & Eº for Cu+2/Cuis 0.15 V )

1. 0.49 V

2. – 0.19 V

3. 0.38 V

4. – 0.38 V

Subtopic:  Electrode & Electrode Potential |
Level 3: 35%-60%
AIPMT - 2000
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A cell reaction become spontaneous when:

1. ∆Gº is negative

2. ∆Gº is positive

3. ERed° is positive

4. ERed° is negative

Subtopic:  Relation between Emf, G, Kc & pH |
 89%
Level 1: 80%+
AIPMT - 2000
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