CUET Chemistry Class 12 Chapter 2 NCERT Solutions – PDF in Hindi & English

Preparing for CUET Chemistry with NCERT requires a clear understanding of concepts as well as regular practice of textbook questions. Electrochemistry, Chapter 2 of Class 12 Chemistry, includes electrochemical cells, electrode potentials, the Nernst equation, conductivity, electrolysis, batteries and corrosion. These topics involve both conceptual questions and numerical applications.

CUET Chemistry Class 12 Chapter 2 NCERT Solutions provide question-wise answers and explanations to help you check your understanding after attempting the exercises. Hindi and English PDFs are also available for convenient revision and quick reference.

Electrochemistry – NCERT Solutions

You can use the following NCERT solutions for Electrochemistry to check your answers, understand the concepts and practise the numerical problems included in Class 12 Chemistry Chapter 2.

Q1. Arrange the metals Mg, Al, Zn, Fe and Cu in the order in which they displace each other from the solutions of their salts.

• (A) Mg > Al > Zn > Fe > Cu

• (B) Cu > Fe > Zn > Al > Mg

• (C) Fe > Zn > Mg > Al > Cu

• (D) Al > Mg > Fe > Zn > Cu

Answer: (A)

Q2. Calculate the molar conductivity of KCl solutions at different concentrations.

The conductivity of KCl solutions at different concentrations at 298 K is given below:

Calculate Λₘ for all concentrations, draw a graph of Λₘ vs c¹ᐟ², and find the value of Λₘ⁰.

Answer: Λₘ⁰ ≈ 124.0 S cm² mol⁻¹

Q3. Calculate the molar conductivity and dissociation constant of acetic acid.

The conductivity of 0.00241 M acetic acid is 7.896 × 10⁻⁵ S cm⁻¹. Calculate its molar conductivity (Λₘ) and dissociation constant (Kₐ) if Λₘ⁰ for acetic acid is 390.5 S cm² mol⁻¹.

• (A) Λₘ ≈ 32.76 S cm² mol⁻¹, Kₐ ≈ 1.85 × 10⁻⁵ mol L⁻¹

• (B) Λₘ ≈ 18.5 S cm² mol⁻¹, Kₐ ≈ 32.76 × 10⁻⁵ mol L⁻¹

• (C) Λₘ ≈ 390.5 S cm² mol⁻¹, Kₐ ≈ 1.85 × 10⁻⁵ mol L⁻¹

• (D) Λₘ ≈ 32.76 S cm² mol⁻¹, Kₐ ≈ 1.85 × 10⁻⁴ mol L⁻¹

Answer: (A)

Q4. Calculate the charge required for the following reductions.

How much charge in Coulombs is required for the following reductions?

1. 1 mol of Al³⁺ to Al

2. 1 mol of Cu²⁺ to Cu

3. 1 mol of MnO₄⁻ to Mn²⁺

Answer:

1. 289,500 C

2. 193,000 C

3. 482,500 C

Q5. Calculate the electricity required in terms of Faraday.

How much electricity in terms of Faraday is required to produce:

1. 20.0 g of Ca from molten CaCl₂?

2. 40.0 g of Al from molten Al₂O₃?

Answer:

1. 1 F

2. 4.44 F

Q6. Calculate the electricity required for oxidation.

How much electricity in Coulombs is required for the oxidation of:

1. 1 mol of H₂O to O₂?

2. 1 mol of FeO to Fe₂O₃?

Answer:

1. 193,000 C

2. 96,500 C

Q7. Calculate the mass of nickel deposited during electrolysis.

A solution of Ni(NO₃)₂ is electrolysed between platinum electrodes using a current of 5 A for 20 minutes. What mass of Ni is deposited at the cathode? (Atomic mass of Ni = 58.7 u)

• (A) 1.825 g

• (B) 2 g

• (C) 5.87 g

• (D) 0.912 g

Answer: (B)

Q8. Calculate the time and masses of metals deposited during electrolysis.

Three electrolytic cells A, B and C containing solutions of ZnSO₄, AgNO₃ and CuSO₄, respectively, are connected in series. A steady current of 1.5 A is passed through them until 1.45 g of silver is deposited at the cathode of cell B. How long did the current flow? What masses of copper and zinc were deposited?

Answer:

• Time: 863.89 s

• Cu: 0.426 g

• Zn: 0.439 g

Q9. Predict whether the following reactions are feasible.

1. Fe³⁺(aq) and I⁻(aq)

2. Ag⁺(aq) and Cu(s)

3. Fe³⁺(aq) and Br⁻(aq)

4. Ag(s) and Fe³⁺(aq)

5. Br₂(aq) and Fe²⁺(aq)

Answer:

1. Feasible

2. Feasible

3. Not feasible

4. Not feasible

5. Feasible

Q10. Predict the products of electrolysis in each of the following.

1. An aqueous solution of AgNO₃ with silver electrodes

2. An aqueous solution of AgNO₃ with platinum electrodes

3. A dilute solution of H₂SO₄ with platinum electrodes

4. An aqueous solution of CuCl₂ with platinum electrodes

Answer:

1. Ag / Ag dissolution

2. Ag / O₂

3. H₂ / O₂

4. Cu / Cl₂

Q11. Arrange the metals in increasing order of their reducing power.

Based on their standard electrode potentials:

• K⁺/K = −2.93 V

• Ag⁺/Ag = 0.80 V

• Hg²⁺/Hg = 0.79 V

• Mg²⁺/Mg = −2.37 V

• Cr³⁺/Cr = −0.74 V

Answer: Ag < Hg < Cr < Mg < K

Q12. Depict the galvanic cell for the given reaction.

Zn(s) + 2Ag⁺(aq) → Zn²⁺(aq) + 2Ag(s)

Further show:

1. Which of the electrodes is negatively charged?

2. What are the carriers of current in the cell?

3. What are the individual reactions at each electrode?

Answer:

• Cell: Zn(s) | Zn²⁺(aq) || Ag⁺(aq) | Ag(s)

• 1. Negatively charged electrode: Zn electrode

• 2. Current carriers: Electrons in the wire and ions in the solution

• 3. Electrode reactions:

• Anode: Zn → Zn²⁺ + 2e⁻

• Cathode: Ag⁺ + e⁻ → Ag

Q13. Calculate the standard cell potential, ΔᵣG°, and equilibrium constant.

Calculate the standard cell potentials, ΔᵣG°, and equilibrium constant (K) for the following reactions at 298 K:

1. 2Cr(s) + 3Cd²⁺(aq) → 2Cr³⁺(aq) + 3Cd(s)

2. Fe²⁺(aq) + Ag⁺(aq) → Fe³⁺(aq) + Ag(s)

Answer:

1. E° = 0.34 V, ΔᵣG° = −196.86 kJ mol⁻¹, K = 3.17 × 10³⁴

2. E° = 0.03 V, ΔᵣG° = −2.89 kJ mol⁻¹, K = 3.22

Q14. Calculate the EMF of the following cell.

Write the Nernst equation and calculate the EMF of the following cell at 298 K:

Mg(s) | Mg²⁺(0.001 M) || Cu²⁺(0.0001 M) | Cu(s)

Answer: 2.68 V

Q15. Calculate E°cell and ΔᵣG° for the button cell.

In the button cell widely used in watches, the following reaction takes place:

Zn(s) + Ag₂O(s) + H₂O(l) → Zn²⁺(aq) + 2Ag(s) + 2OH⁻(aq)

Determine E°cell and ΔᵣG° for the reaction.

• (A) E°cell = 1.10 V, ΔᵣG° = −212.3 kJ mol⁻¹

• (B) E°cell = −1.10 V, ΔᵣG° = 212.3 kJ mol⁻¹

• (C) E°cell = 0.42 V, ΔᵣG° = −81.06 kJ mol⁻¹

• (D) E°cell = 1.50 V, ΔᵣG° = −289.5 kJ mol⁻¹

Answer: (A)

Q16. Define conductivity and molar conductivity.

Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration.

Answer: Conductivity decreases with dilution, while molar conductivity increases with dilution.

Q17. Calculate the molar conductivity of KCl.

The conductivity of a 0.20 M solution of KCl at 298 K is 0.0248 S cm⁻¹. Calculate its molar conductivity.

• (A) 1240 S cm² mol⁻¹

• (B) 12.4 S cm² mol⁻¹

• (C) 0.124 S cm² mol⁻¹

• (D) 124 S cm² mol⁻¹

Answer: (D)

Q18. Calculate the conductivity of a KCl solution.

The electrical resistance of a conductivity cell filled with 0.1 mol L⁻¹ KCl solution is 100 Ω. If the resistance of the same cell when filled with 0.02 mol L⁻¹ KCl solution is 520 Ω, calculate the conductivity of the 0.02 mol L⁻¹ KCl solution. The conductivity of 0.1 mol L⁻¹ KCl solution is 1.29 S m⁻¹.

Alternatively, calculate the cell constant if the conductivity is 0.146 × 10⁻³ S cm⁻¹ and the resistance is 1500 Ω.

• (A) 0.146 cm⁻¹

• (B) 0.219 cm⁻¹

• (C) 1.5 cm⁻¹

• (D) 0.05 cm⁻¹

Answer: (B)

Important Topics in Electrochemistry for CUET Chemistry

You can focus on the following important topics from Electrochemistry for CUET Chemistry, covering the key concepts, formulas and applications that are commonly relevant for revision:

For CUET Chemistry, revise the following NCERT concepts carefully:

• Electrochemical Cells: Understand galvanic and electrolytic cells, their components and working.

• Electrode Potential: Revise standard electrode potential and the Standard Hydrogen Electrode.

• Cell EMF: Practise calculating standard and non-standard cell potentials.

• Nernst Equation: Learn how concentration affects cell potential and practise numerical applications.

• Gibbs Energy and Equilibrium: Revise the relationships between ΔG°, E°cell and equilibrium constant.

• Conductance and Conductivity: Understand resistance, conductance, conductivity and cell constant.

• Molar Conductivity: Revise its variation with concentration for strong and weak electrolytes.

• Kohlrausch's Law: Practise calculating limiting molar conductivity.

• Electrolysis: Revise Faraday's laws and numerical applications.

• Batteries and Fuel Cells: Learn their construction, reactions and applications.

• Corrosion: Understand its electrochemical mechanism and methods of prevention.

Important Questions from Class 12 Chemistry Chapter 2 for CUET 2027

Here are some important NCERT-based questions from Class 12 Chemistry Chapter 2, Electrochemistry, that you can practise for CUET Chemistry 2027 preparation:

Some NCERT-based questions to practise from Electrochemistry include:

1. How is the standard electrode potential of an electrode determined using the Standard Hydrogen Electrode?

2. Why can copper sulphate solution not be stored in a zinc container?

3. How do you calculate the emf of an electrochemical cell under standard conditions?

4. How is the Nernst equation used to calculate cell potential?

5. What is the relationship between standard Gibbs energy change and standard cell potential?

6. How can the equilibrium constant of a cell reaction be calculated from E°cell?

7. What is the difference between resistance, conductance and conductivity?

8. How does molar conductivity vary with dilution?

9. State and apply Kohlrausch's law.

10. How is the amount of substance deposited during electrolysis calculated?

11. What is the role of the salt bridge in a galvanic cell?

12. Differentiate between galvanic and electrolytic cells.

13. What are the important features of primary and secondary batteries?

14. How does a hydrogen-oxygen fuel cell work?

15. What is electrochemical corrosion and how can it be prevented?

CUET Chemistry Class 12 Chapter 2 NCERT Solutions PDF

The CUET Chemistry Chapter 2 NCERT Solutions PDF provides answers to the questions from the Electrochemistry chapter. You can use the solutions after attempting the NCERT questions yourself.

You can download the Electrochemistry NCERT Solutions PDF in your preferred language to practise NCERT questions, check answers and revise important concepts for CUET Chemistry.

How to Use NCERT Solutions for CUET Chemistry Preparation 2027?

Use the Class 12 Chemistry Chapter 2 NCERT Solutions alongside your NCERT textbook rather than relying on the answers alone.

• Read the Electrochemistry chapter: Understand the concepts and equations before solving the exercises.

• Attempt the questions yourself: Work through conceptual questions and numericals without checking the answer first.

• Check each solution: Compare your method with the NCERT solution and identify calculation or concept-based errors.

• Revise important formulas: Keep the Nernst equation, cell potential, conductivity, molar conductivity and Faraday's law ready for quick revision.

• Practise NCERT-based questions: Use textbook concepts as the foundation for CUET Chemistry practice.

• Use the PDF for revision: Keep the English or Hindi PDF available for quick reference during revision sessions.

• Reattempt difficult questions: Solve questions you got wrong after revising the relevant NCERT concept.

Electrochemistry is an important chapter for CUET Chemistry 2027, covering concepts such as electrochemical cells, electrode potential, conductivity, electrolysis, batteries and corrosion. Practising NCERT questions and reviewing their solutions can help you strengthen these concepts, revise important formulas and improve your accuracy in CUET Chemistry.

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