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

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 K_a 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

A dilute solution of $H_2<mspace\; width="1em"></mspace>S{O}_4$ 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

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

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?

A 100 mL solution of 0.1 M HBr is titrated using a very concentrated NaOH solution. Assuming that the change in volume due to the addition of NaOH is negligible, calculate the specific conductivity (κ) of the solution at the equivalence point.

Given:

Λ°Na⁺ = 8 × 10⁻³ S m² mol⁻¹

Λ°Br⁻ = 4 × 10⁻³ S m² mol⁻¹

Express the answer in terms of 10⁻¹ S m⁻¹.

1.   06                               
2.   12
3.   15                             
4.   24

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

A propane fuel cell converts the chemical energy released during the combustion of propane into electrical energy.
Given the standard Gibbs free energies of formation:

Calculate the standard EMF (E_cell∘​) of the propane fuel cell.

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

The temperature coefficient of a standard Cd-cell is $–5.0<mspace\; width="1em"></mspace>\times <mspace\; width="1em"></mspace>{10}^{-5}<mspace\; width="1em"></mspace>V{k}^{-1}$ whose emf at $25°C$ is 1.018 V. During the cell operation, the temperature will -

(1) increase                                      

(2) decreases

(3) either                                         

(4) remains constant

Na-amalgam is prepared by electrolysis of NaCl solution using liquid Hg as a cathode. How long should the current of 10 amp. is passed to produce 10% Na – Hg on a cathode of 10 gm Hg. (atomic mass of Na = 23).

1.   7.77 min.                                               
2.   9.44 min.
3.   5.24 min.                                               
4.   11.39 min.