MCQ Questions for Class 12 Chapter Wise with Answers were Prepared based on Latest Exam Pattern and syllabus. Students can solve Class 12 MCQ Questions with Answers to know their preparation level. Electrochemistry is worried about charges with their development and movement starting with one medium then onto the next. An ultimate unit of charge is that conveyed by the electron, electrons are significant in electrochemistry and their capacities here are like a portion of those which they display in related teaches all the more normally viewed as the area of physics.

Important Class 12 Chemistry MCQ Questions of Electrochemistry with Answers are available here by Sarthaks eConnect. It helps students understand the concept very well.  Refer to more Chapter-wise MCQ Questions for Class 12 Chemistry Electrochemistry for all subjects.

Practice MCQ Question for Class 12 Chemistry chapter-wise

1. If 96500 coulomb electricity is passed through CuSO₄ solution, it will liberate

(a) 63.5 gm of Cu
(b) 31.76 gm of Cu
(c) 96500 gm of Cu
(d) 100 gm of Cu

2. Fused NaCl on electrolysis gives ………….. on cathode.

(a) Chlroine
(b) Sodium
(c) Sodium amalgam
(d) Hydrogen

3. Which of the following is a secondary cell?

(a) Leclanche cell
(b) Lead storage battery
(c) Concentration cell
(d) All of these

4. Faraday’s law of electrolysis is related to

(a) Atomic number of cation
(b) Speed of cation
(c) Speed of anion
(d) Equivalent weight of electrolyte

5. How much electricity in terms of Faraday is required to produce 100 g of Ca from molten CaCl₂?

(a) 1F
(b) 2F
(c) 3F
(d) 5F

6. How many coulombs of electricity is required to reduce 1 mole of \(Cr_2O_7^{2-}\)in acidic medium?

(a) 4 \(\times\) 96500 C
(b) 6 \(\times\) 96500 C
(c) 2 \(\times\) 96500 C
(d) 1 \(\times\) 96500 C

7. Effect of dilution on conductivity of solution:

(a) Increases
(b) Decreases
(c) Unchanged
(d) None of the above

8. What flows in the internal circuit of a galvanic cell?

(a) Ions
(b) Electrons
(c) Electricity
(d) Atoms

9. Which of the following statements about galvanic cell is incorrect

(a) anode is positive
(b) oxidation occurs at the electrode with lower reduction potential
(c) cathode is positive
(d) reduction occurs at cathode

10. The electric charge for electrode decomposition of one gram equivalent of a substance is

(a) one ampere per second
(b) 96500 coulombs per second
(c) one ampere for one hour
(d) charge on one mole of electrons

11. In electrolysis of dilute H₂SO₄ using platinum electrodes

(a) H₂ is evolved at cathode
(b) NH₂ is produced at anode
(c) Cl₂ is obtained at cathode
(d) O₂ is produced

12. The difference between the electrode potentials of two electrodes when no current is drawn through the cell is called.............

(a) Cell potentials
(b) Cell emf
(c) Potential difference
(d) Cell voltage

13. The reference electrode is made by using

(a) ZnCl₂
(b) CuSO₄
(c) HgCl₂
(d) Hg₂Cl₂

14. The standard hydrogen electrode potential is zero, because

(a) hydrogen oxidized easily
(b) electrode potential is considered as zero
(c) hydrogen atom has only one electron
(d) hydrogen is a very light element

15. Without losing its concentration ZnCl₂ solution cannot be kept in contact with

(a) Au
(b) Al
(c) Pb
(d) Ag

16.  Standard electrode potential of three metals X, Y and Z are – 1.2 V, + 0.5 V and  – 3.0 V, respectively. The reducing power of these metals will be :

(a) Y > Z > X
(b) X > Y > Z
(c) Z > X > Y
(d) X > Y > Z

17. Standard electrode potential for Sn⁴⁺/ Sn²⁺ couple is + 0.15 V and that for the Cr³⁺/ Cr couple is – 0.74 V. These two couples in their standard state are connected to make a cell. The cell potential will be

(a) + 1.19 V
(b) + 0.89 V
(c) + 0.18 V
(d) + 1.83 V

18. The oxidation potentials of A and B are +2.37 and +1.66 V respectively. In chemical reactions

(a) A will be replaced by B
(b) A will replace B
(c) A will not replace B
(d) A and B will not replace each other

19. Which of the following statement is not correct about an inert electrode in a cell?

(a) It does not participate in the cell reaction
(b) It provides surface either for oxidation or for reduction reaction
(c) It provides surface for conduction of electrons
(d) It provides surface for redox reaction

20. Which of the following is the use of electrolysis?

(a) Electrorefining
(b) Electroplating
(c) Both (a) & (b)
(d) None of these

21. The amount of electricity that can deposit 108 g of Ag from AgNO₃ solution is:

(a) 1 F
(b) 2 A
(c) 1 C
(d) 1 A

22. The cell constant of a conductivity cell..................

(a) changes with change of electrolyte
(b) changes with change of concentration of electrolyte
(c) changes with temperature of electrolyte
(d) remains constant for a cell

23. The standard reduction potential at 298K for the following half cells are given: Which is the strongest reducing agent?

(a) Zn(s)
(b) Cr(s)
(c) Both
(d) None of these

24. In electroplating the article to be electroplated is made 

(a) cathode
(b) anode
(c) either cathode or anode
(d) simply suspended in the electrolytic bath

25. A device that converts energy of combustion of fuels like hydrogen and methane, directly into electrical energy is known as : 

(a) Fuel cell
(b) Electrolytic cell
(c) Dynamo
(d) Ni -Cd cell

Answer :

1. Answer : (b) 31.76 gm of Cu

Explanation: 

At the cathode

\(Cu^{2+}(aq)+2e^-\longrightarrow\)\(Cu(s)\)

At the anode

\(4OH^-(aq)\longrightarrow\)​ \(2H_2O(l)+O_2(g)+4e^-\)

​​​​​​Faraday’s constant = 96500C / mol

To deposit 1 mole of copper, we need \(2\times96500\) So, 96500C will deposit 0.5 moles of copper

\(=0.\times63.5=31.75g\)

2. Answer : (b) Sodium

Explanation: Fused on electrolysis gives on cathode gives sodium.

3. Answer : (b) Lead storage battery

Explanation: Lead storage cells and nickel-cadmium cells are examples of secondary cells.

4. Answer : (d) Equivalent weight of electrolyte

Explanation: Equivalent weight is the ratio of the atomic mass of metal and the number of electrons that are required for the reduction of the cation. Hence, Faraday's law of electrolysis is related to the equivalent mass of electrolyte.

5. Answer : (d) 5F

Explanation: \(CaCl_2\longrightarrow\)​​​​​​ \(Ca^{2+}+2Cl^-\)​

Ca is undergoing oxidation i.e,

 \(Ca^{2+}+2e^-\longrightarrow\)​​​​​​ \(Ca\)

We can observe that 40g of Ca takes \(2e^-\) charge,

Now, 100g of Ca = 5F

6. Answer : (b) 6 \(\times\) 96500 C 

Explanation: In acidic medium dichromate ions undergoes reduction and the reaction is,

\(Cr_2O_7+14H^++6e^-\longrightarrow\)​ \(2Cr^{3+}+7H_2O\)

So, 1 mole of  \(Cr_2O_7^{2-}\)​ ​​​​ion requires 6 moles of electrons i.e. 6 \(\times\) 96500 C of electricity.

7. Answer : (a) Increases

Explanation: When a solution is diluted, there are more ions and they have more space to move, i.e. ions are more far away from each other and mobility of ions increase which leads to increase in molar conductivity of the solution. Hence when a solution is diluted, conductivity decreases and molar conductivity increases.

8. Answer : (a) Ions

Explanation: The galvanic cell's two fundamental components will be these two electrodes. The reduction half-reaction should happen at the cathode, whereas the oxidation half-reaction should happen at the anode. Therefore, ions flow in the inner circuit or the internal circuit of the galvanic cell.

9. Answer : (a) anode is positive

Explanation: Anode has negative polarity in galvanic cell.

10. Answer : (d) charge on one mole of electrons

Explanation: Charge on one mole of electrons is equal to one Faraday, so one gram equivalent of a substance will be deposited by one mole of electrons. 1 g equivalent of a substance means one equivalent of substance which have total charge of one mole of electron.

11. Answer : (a) H₂ is evolved at cathode

Explanation: H₂ is liberated at Cathode while O₂ is liberated at anode.

12. Answer : (b) Cell emf

Explanation: Cell emf is the energy provided by a cell or battery per coulomb of charge passing through it.So, the difference between the electrode potentials of two electrodes when no current is drawn through the cell is called cell emf.

13. Answer : (d) Hg₂Cl₂

Explanation: The most commonly used reference electrode is calomel electrode. Its reduction potential depends upon the concentration of KCl solution used. The calomel electrode is made by using Hg₂Cl₂.

14. Answer : (b) electrode potential is considered as zero

Explanation: In electrochemistry, hydrogen is taken to be the reference to measure the potential and hence to form a basis for comparison with all other electrode reactions, hydrogen's standard electrode potential is declared to be zero volts at all temperatures.

15. Answer : (b) Al

Explanation: Only Al(E^∘=−1.66V) has lower electrode potential than Zn(E^∘ =−0.76V) and hence it will reduce Zn ²⁺ to Zn while all others have higher electrode potentials than Zn.

16. Answer : (d) X > Y > Z

Explanation: Higher the reduction potential lesser is reducing power and vice-versa. Hence, the order of reducing power is Z > X > Y.

17. Answer : (b) + 0.89 V

Explanation: E^∘_cell = E^∘_{cathode (RP)} − E^∘_{anode (RP)}

​​​​​= 0.15 − (−0.74) 

= + 0.89 V

18. Answer : (b) A will replace B

Explanation: A metal with higher O.P. (i.e. A) replaces a metal with lower O.P. (i.e. B) from its aqueous solution.

19. Answer : (d) It provides surface for redox reaction

Explanation: The inert electrode is an electrode that serves only as a source or sinks for electrons. Precious metals, mercury, and carbon are typically used as inert electrodes. It provides a surface for oxidation or reduction reaction but not for the redox reaction.

20. Answer : (d) None of these

Explanation: The main application of electrolysis are: Electrorefining, Electroplating, Extraction of metals.

21. Answer : (a) 1 F

Explanation: 1 Faraday of charge discharges E gram of an ion, where E is the equivalent weight. For silver, the value of  E is 108 g. Thus, the amount of electricity that can deposit 108 g of silver form AgNO₃ solution is one Faraday.

22. Answer : (d) remains constant for a cell

Explanation: The cell constant, K, is equal to the distance in cm between the probe's electrodes divided by the surface area of the electrodes in cm² .For solutions with low conductivities the electrodes can be placed closer together or made larger so that the cell constant is less than one.

23. Answer : (a) Zn(s)

Explanation: Zinc is the strongest reducing agent in the following above given reactions because the standard reduction potentials of the Zinc, which is given, is the most negative than others.

24. Answer : (a) cathode

Explanation: The material to be electroplated, should be made cathode. The positive radical from the electrolyte goes to the cathode and gets deposited there by reduction process.

25. Answer : (a) Fuel cell

Explanation: A fuel cell is a device that converts the energy of combustion of fuels like hydrogen and methane, directly into electrical energy. Electrolytic cell converts electrical energy into chemical energy.

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