The reduction potential of a half-cell consisting of a Pt electrode immersed in \(1.5 \text{M}~ F e^{2+} \text { and } 0.015 \text{M}~ F e^{3+}\) solution at 25 oC is:
\((E_{F e^{+3}, F e^{+2}}^{\circ}=+0.770 ~V )\)
1.   0.652 V                                                   
2.   0.88 V
3.   0.710 V                                                   
4.   0.850 V

Subtopic:  Nernst Equation |
 61%
Level 2: 60%+
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In a concentration cell, Zn/Zn2+(1.0M)||Zn2+(0.15M)/Zn as the cell discharges,

(1) reaction proceeds to the right

(2) the two solutions approach each other in concentration

(3) no reaction takes place

(4) water gets decomposed

Subtopic:  Electrode & Electrode Potential |
 59%
Level 3: 35%-60%
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In a half-cell containing \(\left[T l^{3+}\right]=0.1 M \text { and }\left[T l^{+}\right]=0.01 \mathrm{M},\) the cell potential is – 1.2496 V for the reaction \(T l^{+} \rightarrow T l^{3+}+2 e^{-}\). The standard reduction potential of the \(T l^{+} / T l^{3+}\) couple at  25 ° C is :

1.   1.44 V                                          
2.   0.61 V
3.   2.44 V                                          
4.   1.22 V

Subtopic:  Nernst Equation |
 74%
Level 2: 60%+
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Given cell: 

Pt(s)|H2(g)(P = 1 atm)| CH3COOH(0.1 M), HCl(0.1 M) || KCl(aq)|Hg2Cl2(s)|Hg

EMF of the cell is found to be 0.045 V at 298 K and the temperature coefficient is 3.4×10-4 V K-1. The cell entropy change of the following cell is : 

[Given Ka CH3COOH = 10-5  M]

1. 70.8 J K−1 mol−1                      

2. 65.2 J K−1 mol−1

3. 79.2 J K−1 mol−1                  

4. 83.5 J K−1 mol−1

Subtopic:  Relation between Emf, G, Kc & pH |
 62%
Level 2: 60%+
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A dilute solution of H2SO4 was electrolysed by passing a current of 2 amp. The time required for formation of 0.5 mole of oxygen is :

1.   26.8 hours                                    

2.   13.4 hours

3.   6.7 hours                                      

4.   28.6 hours

Subtopic:  Faraday’s Law of Electrolysis |
 53%
Level 3: 35%-60%
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The standard reduction potentials of Mn³⁺/Mn²⁺ and MnO₂/Mn³⁺ couples in acidic medium at 25°C are 1.50 V and 1.00 V, respectively. For the reaction:

2Mn³⁺ + 2H₂O → Mn²⁺ + MnO₂ + 4H⁺.

Find the nature of the reaction:

1.  Reversible                                             

2.  Non-spontaneous

3.  Spontaneous                                         

4.  Irreversible

Subtopic:  Electrode & Electrode Potential |
 76%
Level 2: 60%+
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Consider the electrochemical cell at 25 °C:

M | M⁺ || X⁻ | X

The standard reduction potentials are:

E°(M⁺/M) = 0.52 V
E°(X/X⁻) = 0.42 V

Which of the following statements is correct?

1. M + X → M⁺ + X⁻ is spontaneous.
2. M⁺ + X⁻ → M + X is spontaneous.
3. E°cell = 0.77 V
4. E°cell = −0.77 V

Subtopic:  Electrode & Electrode Potential |
 67%
Level 2: 60%+
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If a 100 mL solution of 0.1M HBr is titrated using a very concentrated solution of NaOH, when the conductivity (specific conductance) of the solution at the equivalence point will be:
Calculate your answer in terms of 10-1Sm-1
(Assume volume change is negligible due to addition of NaOH).
\(\text { Given } \wedge^{\circ} \mathrm{Na}^{+}=8 \times 10^{-3} \mathrm{S~m}^2 \mathrm{~mol}^{-1}; \wedge^{\circ}{ }_{\mathrm{Br}}=4 \times 10^{-3} \mathrm{~S} \mathrm{~m}^2 \mathrm{~mol}^{-1}\)

1.   6                               
2.   12
3.   15                             
4.   24

Subtopic:  Conductance & Conductivity |
 74%
Level 2: 60%+
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The volume of gases liberated at STP when a charge of 2F is passed
through aqueous solution of sodium phosphate, is :

1. 11.2L                                           

2. 44.8L

3. 33.6L                                           

4. 22.4L

Subtopic:  Faraday’s Law of Electrolysis |
Level 3: 35%-60%
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It is desired to convert the energy derived from the combustion of propane into electrical energy, via a fuel cell. Given that the standard free energies of formation of C3H8(g),H2O(l)andCO2(g) are -23.5, -237.2 and -394.4 kJmol-1 respectively, calculate the standard EMF of the propane fuel cell.

1.   1.10 V                                           
2.   2.10 V
3.   3.12 V                                           
4.   4.12 V

Subtopic:  Relation between Emf, G, Kc & pH |
 53%
Level 3: 35%-60%
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