A button cell used in watches functions as following
Zn(s) + Ag2O(s) + H2O(l) \(\rightleftharpoons\) 2Ag(s) + Zn2+(aq) + 2OH(aq)
If half-cell potentials are-

Zn2+(aq) + 2e→ Zn(s)  Eo = – 0.76 V 
Ag2O(s) + H2O(l) + 2e → 2Ag(s) + 2OH(aq) Eo = 0.34 V

The cell potential will be:

1. 0.42 V 2. 0.84 V
3. 1.34 V 4. 1.10 V
Subtopic:  Electrode & Electrode Potential |
 87%
Level 1: 80%+
AIPMT - 2013
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Consider the half-cell reduction reaction:
\(\text{Mn}^{2+}+2e^-\rightarrow \text{Mn},\ E^{0}= -1.18~ \text V \) 
\(\text{Mn}^{2+}\rightarrow \text{Mn}^{3+}+e^-,\ E^{0}= -1.5~ \text V \)

The \(E^{0}\) for the reaction \(\mathrm{3\ Mn^{2+}\rightarrow Mn^{0}+2Mn^{3+} }\) and possibility of the forward reaction are respectively:
 
1. –4.18 V and Yes 2. +0.33 V and Yes
3. +2.69 V and No 4. –2.69 V and No
Subtopic:  Electrode & Electrode Potential |
 54%
Level 3: 35%-60%
NEET - 2013
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Standard electrode potential of three metals X, Y and Z are -1.2 V, +0.5 V and -3.0 V respectively. The reducing power of these metals will be: 
1. Y > X > Z 2. Z > X > Y
3. X > Y > Z 4. Y > Z > X
Subtopic:  Electrode & Electrode Potential |
 82%
Level 1: 80%+
AIPMT - 2011
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Based on electrode potentials in the table below: 
Cu2+(aq) + e- → Cu+(aq) 0.15 V
Cu+(aq) + e- → Cu(s) 0.50 V

The value of \(E_{Cu^{2+}/Cu}^{o}\) will be:
1. 0.325 V 2. 0650 V
3. 0.150 V 4. 0.500 V
Subtopic:  Electrode & Electrode Potential |
 63%
Level 2: 60%+
AIPMT - 2011
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Standard electrode potential for Sn4+/Sn2+ couple is +0.15 V and that for Cr3+/Cr couple is -0.74. These two couples in their standard state are connected to make a cell. The cell potential will be:

1. +0.89 V

2. +0.18 V

3. +1.83 V

4. +1.199 V

Subtopic:  Electrode & Electrode Potential |
 91%
Level 1: 80%+
AIPMT - 2011
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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) + (Reduction potential of cathode)
(c) emf of cell = (Reduction potential of anode) + (Reduction potential of cathode)
(d) emf of cell = (Oxidation potential of anode) – (Oxidation potential of 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 |
 70%
Level 2: 60%+
AIPMT - 2010
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If EFe2+/Feo = -0.441 V and  EFe3+/Fe2+o = 0.771 V, the standard emf of the reaction: 

Fe + 2Fe3+→ 3Fe2+ will be:

1. 0.330 V 2. 1.653 V
3. 1.212 V 4. 0.111 V
Subtopic:  Electrode & Electrode Potential |
 74%
Level 2: 60%+
AIPMT - 2006
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