Read and download the CBSE Class 12 Chemistry Electrochemistry Notes and Questions for the 2025-26 academic session. We have provided comprehensive Class 12 Chemistry school assignments that have important solved questions and answers for Unit 2 Electrochemistry. These resources have been carefuly prepared by expert teachers as per the latest NCERT, CBSE, and KVS syllabus guidelines.
Solved Assignment for Class 12 Chemistry Unit 2 Electrochemistry
Practicing these Class 12 Chemistry problems daily is must to improve your conceptual understanding and score better marks in school examinations. These printable assignments are a perfect assessment tool for Unit 2 Electrochemistry, covering both basic and advanced level questions to help you get more marks in exams.
Unit 2 Electrochemistry Class 12 Solved Questions and Answers
Kohlrausch law of independent migration of ions. The law states that limiting conductivity of an electrolyte can be represented as the sum of the individual contribution to the anion and cation of the electrolyte.
Faraday’s laws of Electrolysis
I. The amount of chemical reaction which occurs at any electrode during electrolysis by a current is proportional to the quantity of electricity passed through the electrolyte.
II. The amount of different substances liberated by the same quantity of electricity passing through the electrolytic solution is proportional to their chemical equivalent weights. Batteries and full cells are very useful forms of galvanic cells There are mainly two types of batteries.
Corrosion of metals is an electrochemical phenomenon In corrosion metal is oxidized by loss of electrons to oxygen and formation of oxides.
Anode (Oxidation): 2Fe(s) →2Fe2+ + 4e-
Cathode (Reduction): O2(g) + 4H+(aq) + 4e-→2H2O
Atmospheric Oxidation:
2Fe2+(aq) + 2H2O(l) + 1/2O2(g)→Fe2O3(s) + 4H+(aq)
1. What is the effect of temperature on molar conductivity?
Ans. Molar conductivity of an electrolyte increases with increase in temperature.
2. Why is it not possible to measure single electrode potential?
Ans. (It is not possible to measure single electrode potential because the half cell containing single electrode cannot exist independently, as charge cannot flow on its own in a single electrode.)
3. Name the factor on which emf of a cell depends:-
Ans. Emf of a cell depends on following factora. Nature of reactants.
b. Concentration of solution in two half cells.
d. Pressure of gas.
4. What are the units of molar conductivity?
5. What is the EMF of the cell when the cell reaction attains equilibrium?
Ans. Zero
6. What is the electrolyte used in a dry cell?
Ans. A paste of NH4Cl, MnO2 and C
7. How is cell constant calculated from conductance values?
Ans. Cell constant= specific conductance/ observed conductance.
8. What flows in the internal circuit of a galvanic cell.
Ans. Ions
9. Define electrochemical series.
Ans. The arrangement of various electrodes in the decreasing or increasing order of their standard reduction potentials is called electrochemical series.
QUESTIONS CARRYING TWO MARKS
1. How can you increase the reduction potential of an electrode.? For the reaction
a. increase in concentration of Mn+ ions in solution
b. by increasing the temperature.
2. Calculate emf of the following cell at 298K
Question The weight of silver (at. wt. = 108) displaced by a quantity of electricity which displaces 5600 mL of O2 at STP will be
(a) 5.4 g
(b) 10.8 g
(c) 54.0 g
(d) 108.0 g
Question. How many grams of cobalt metal will be deposited when a solution of cobalt(II) chloride is electrolyzed with a current of 10 amperes for 109 minutes?(1 Faraday = 96,500 C; Atomic mass of Co = 59 u)
(a) 4.0
(b) 20.0
(c) 40.0
(d) 0.66
Question. Al2O3 is reduced by electrolysis at low potentials and high currents. If 4.0 × 104 amperes of current is passed through molten Al2O3 for 6 hours, what mass of aluminium is produced? (Assume 100% current efficiency, at. mass of Al = 27 g mol–1)
(a) 8.1 × 104 g
(b) 2.4 × 105 g
(c) 1.3 × 104 g
(d) 9.0 × 103 g
Question. 4.5 g of aluminium (at. mass 27 amu) is deposited at cathode from Al3+ solution by a certain quantity of electric charge. The volume of hydrogen produced at STP from H+ ions in solution by the same quantity of electric charge will be
(a) 44.8 L
(b) 22.4 L
(c) 11.2 L
(d) 5.6 L
Question. In electrolysis of NaCl when Pt electrode is taken then H2 is liberated at cathode while with Hg cathode it forms sodium amalgam. The reason for this is
(a) Hg is more inert than Pt
(b) more voltage is required to reduce H+ at Hg than at Pt
(c) Na is dissolved in Hg while it does not dissolve in Pt
(d) conc. of H+ ions is larger when Pt electrode is taken.
Question. A 5 ampere current is passed through a solution of zinc sulphate for 40 minutes. The amount of zinc deposited at the cathode is
(a) 0.4065 g
(b) 65.04 g
(c) 40.65 g
(d) 4.065 g
Question. Sodium is made by the electrolysis of a molten mixture of about 40% NaCl and 60% CaCl2 because
(a) Ca++ can reduce NaCl to Na
(b) Ca++ can displace Na from NaCl
(c) CaCl2 helps in conduction of electricity
(d) this mixture has a lower melting point than NaCl.
Question. When CuSO4 is electrolysed using platinum electrodes,
(a) copper is liberated at cathode, sulphur at anode
(b) copper is liberated at cathode, oxygen at anode
(c) sulphur is liberated at cathode, oxygen at anode
(d) oxygen is liberated at cathode, copper at anode.
Question. On electrolysis of dilute sulphuric acid using platinum electrodes, the product obtained at the anode will be
(a) hydrogen
(b) oxygen
(c) hydrogen sulphide
(d) sulphur dioxide
Question. A device that converts energy of combustion of fuels like hydrogen and methane, directly into electrical energy is known as
(a) dynamo
(b) Ni-Cd cell
(c) fuel cell
(d) electrolytic cell.
Question. The efficiency of a fuel cell is given by
(a) ΔG/DS
(b) ΔG/DH
(c) ΔS/DG
(d) ΔH/DG
Question. Zinc can be coated on iron to produce galvanized iron but the reverse is not possible. It is because
(a) zinc is lighter than iron
(b) zinc has lower melting point than iron
(c) zinc has lower negative electrode potential than iron
(d) zinc has higher negative electrode potential than iron.
Question. The most convenient method to protect the bottom of ship made of iron is
(a) coating it with red lead oxide
(b) white tin plating
(c) connecting it with Mg block
(d) connecting it with Pb block.
Question. To protect iron against corrosion, the most durable metal plating on it, is
(a) copper plating
(b) zinc plating
(c) nickel plating
(d) tin plating.
Question. Effect of dilution on conductivity of solution:
(a) Increases
(b) Decreases
(c) Unchanged
(d) None of the above
Question. Through a solution of CuSO4 a current of 3 amperes was passed for 2 hours. At cathode 3 g of Cu2+ions were discharged. The current efficiency is [At. wt. of Cu = 63.5]
(a) 33.3%
(b) 42.2%
(c) 48.7%
(d) 54.4%
Question. Which shows electrical conductance?
(a) Sodium
(b) Diamond
(c) Potassium
(d) Graphite
Question. Which cannot displace hydrogen from its compound?
(a) Al
(b) Fe
(c) Hg
(d) Pb
Question. For reducing one mole of Cr2O72- to Cr3+ the charge required is :
(a) 3 × 96500 coulomb
(b) 6 ×96500 coulomb
(c) 0.3 Faradays
(d) 0.6 Faradays
| CBSE Class 12 Chemistry Solutions Assignment Set A |
| CBSE Class 12 Chemistry Solutions Assignment Set B |
| CBSE Class 12 Chemistry Solutions Questions |
| CBSE Class 12 Chemistry Halo Alkanes and Halo arenes Assignment |
| CBSE Class 12 Chemistry Halo Alkanes and Halo arenes Questions |
| CBSE Class 12 Chemistry Alcohols Phenols and Ethers Assignment |
| CBSE Class 12 Chemistry Alcohols Phenols and Ethers Questions |
| CBSE Class 12 Chemistry Aldehydes Ketons Carboxylic Acids Questions |
| CBSE Class 12 Chemistry Biomolecules Assignment |
| CBSE Class 12 Chemistry Biomolecules Notes and Questions |
| CBSE Class 12 Chemistry Biomolecules Questions |
Important Practice Resources for Class 12 Chemistry
CBSE Class 12 Chemistry Unit 2 Electrochemistry Assignment
Access the latest Unit 2 Electrochemistry assignments designed as per the current CBSE syllabus for Class 12. We have included all question types, including MCQs, short answer questions, and long-form problems relating to Unit 2 Electrochemistry. You can easily download these assignments in PDF format for free. Our expert teachers have carefully looked at previous year exam patterns and have made sure that these questions help you prepare properly for your upcoming school tests.
Benefits of solving Assignments for Unit 2 Electrochemistry
Practicing these Class 12 Chemistry assignments has many advantages for you:
- Better Exam Scores: Regular practice will help you to understand Unit 2 Electrochemistry properly and you will be able to answer exam questions correctly.
- Latest Exam Pattern: All questions are aligned as per the latest CBSE sample papers and marking schemes.
- Huge Variety of Questions: These Unit 2 Electrochemistry sets include Case Studies, objective questions, and various descriptive problems with answers.
- Time Management: Solving these Unit 2 Electrochemistry test papers daily will improve your speed and accuracy.
How to solve Chemistry Unit 2 Electrochemistry Assignments effectively?
- Read the Chapter First: Start with the NCERT book for Class 12 Chemistry before attempting the assignment.
- Self-Assessment: Try solving the Unit 2 Electrochemistry questions by yourself and then check the solutions provided by us.
- Use Supporting Material: Refer to our Revision Notes and Class 12 worksheets if you get stuck on any topic.
- Track Mistakes: Maintain a notebook for tricky concepts and revise them using our online MCQ tests.
Best Practices for Class 12 Chemistry Preparation
For the best results, solve one assignment for Unit 2 Electrochemistry on daily basis. Using a timer while practicing will further improve your problem-solving skills and prepare you for the actual CBSE exam.
You can download free Pdf assignments for CBSE Class 12 Chemistry Unit 2 Electrochemistry from StudiesToday.com
All topics given in Unit 2 Electrochemistry Chemistry Class 12 Book for the current academic year have been covered in the given assignment
No, all Printable Assignments for Unit 2 Electrochemistry Class 12 Chemistry have been given for free and can be downloaded in Pdf format
Latest syllabus issued for current academic year by CBSE has been used to design assignments for Unit 2 Electrochemistry Class 12
Yes, we have provided detailed answers for all questions given in assignments for Unit 2 Electrochemistry Class 12 Chemistry