Test: Thermodynamics of Electrochemistry - JEE MCQ

Given ,

Thus ,(log K_eq) for the reaction   Cu²⁺ +In²⁺  Cu⁺ + In³⁺ is   

An excess of liquid mercury is added to an acidified solution of 1.0 x 10^-3 M Fe³⁺ .Thus  is if 5% of Fe³⁺ remains at equilibrium at 298 K

EMF of the following cell is 0.2905 V

Zn/Zn²⁺ (a = 0.1M)|| Fe²⁺ (a = 0.01M)| Fe

 The equilibrium constant for the cell reaction is   

[IIT JEE 2004]

The half-cell reactions for rusting of iron are

ΔG^° (in kJ) for the reaction is     

[IIT JEE 2005]

The Gibbs free energy for the decomposition of Al₂O₃ at 800 K is as follows :

2Al₂O₃ → 4Al + 3O₂ , Δ_rG = 2898kJ mol^-1

The potential difference needed for electrolytic reduction of Al₂O₃ is at least  

Given ,  

The value of standard electrode potential for the half-reaction is

Fe³⁺(aq) + e^- → Fe²⁺(aq) 

For the reaction, 2H₂(g) + O₂(g) → 2H₂O(l), E⁰_cell = 1.23 V at 298 K 

and  ΔH⁰_f (H₂O) = - 285.8 kJ mol^-1 Thus, ΔS^° (standard entropy change ) is  

For the reaction ,

Thus , for the reaction 

Consider the following equations for a cell reaction. 

A+B  C+ D, E⁰ = x volt, K_eq = K₁

2A +2B  2C+ 2D, E⁰ = y volt, K_eq = K₂

Then,   

Which of the following statements about the spontaneous reaction occurring in a galvanic cell is always true?

For a (Ag-Zn) button cell ,the net reaction is 

Zn(s) + Ag₂O(s) → ZnO(s) + 2Ag(s)

ΔG⁰_f(Ag₂O) = -11.21kJmol^-1,  ΔG⁰ _f(ZnO) = - 318.3 kJ mol^-1

Hence, E^°_cell of the button cell is  

For the reaction ,

Thus  

Matching List Type

Choices for the correct combination of elements from Column I and Column II are given as options (a), (b), (c) and (d), out of which one is correct

Q.

The standard reduction potential data at 298 K is given below:

Match E^° of a redox pair in Column I with the values given in Column II and select the corect answer using the codes given below:

The standard potential of the following cell is 0.23 V at 288 K and 0.21 V at 308 K. 

Match the parameters in Column I with their values in Column II and select the answer from the codes given below the list.

Comprehension Type

This section contains a passage describing theory, experiments, data, etc. Two questions related to the paragraph have been given. Each question has only one correct answer out of the given 4 options (a), (b), (c) and (d)  

Passage I

The concentration of potassium ions inside a biological cell is at least twenty times higher than the outside. The resulting potential difference across the cell is important in several process such as transmission of nerve impulses and maintaining the ion balance. A simple model for such a concentration cell involving a metal M is

M(s) | M⁺ (aq, 0.05M), || M⁺(aq) 1M|M(s) | E_cell | = 77mV

Q.

For the above cell,

Passage I

The concentration of potassium ions inside a biological cell is at least twenty times higher than the outside. The resulting potential difference across the cell is important in several process such as transmission of nerve impulses and maintaining the ion balance. A simple model for such a concentration cell involving a metal M is

M(s) | M⁺ (aq, 0.05M), || M⁺(aq) 1M|M(s) | E_cell | = 77mV

Q.

If 0.05 M solution of M⁺ is replaced by 0.0025 M solution of M⁺,then |E_cell | would be  

Passage II 

Given,

ΔG⁰_f(AgCl) = -109kJmol^-1, ΔG⁰_f(Cl^-) = -129kJmol^-1

ΔG⁰_f(Ag⁺) = 77kJmol^-1,

Thus E^°_cell of the cell reaction is  

Ag⁺(aq) + Cl^-(aq) → AgCl(s) is  

Passage II 

Given,

ΔG⁰_f(AgCl) = -109kJmol^-1, ΔG⁰_f(Cl^-) = -129kJmol^-1

ΔG⁰_f(Ag⁺) = 77kJmol^-1,

Q.

K_sp of AgCl is thus,

One Integer Value Correct Type

This section contains 3 questions, when worked out will result in an integer value from 0 to 9 (both inclusive)

Q.

A platinum electrode is immersed in a solution containing 0.1 M Fe²⁺ and 0.1 M Fe³⁺.It iscoupled with SHE.Concentration Fe³⁺ of increased to 0.1 M without change in [Fe²⁺], then the change in EMF (in centivolt) is 

Using Cr₂O₇^2- aqueous, solution  
E⁰_red = 1.33V and ΔG⁰ = -770.07 kJmol^-1

What is the valency of the ion formed after reduction?  

  Equilibriumconstant of the cell reaction,

Cu + 2Fe³⁺  2Fe²⁺ + cu²⁺ is y x 10¹⁴

 What is the value of y?