In electrochemistry, the idea of standard electrode potential MCQs class 12 plays a crucial role in explaining how redox reactions occur in electrochemical cells. For aspirants preparing for board exams and competitive tests, a strong conceptual grip is essential, which is why resources like standard electrode potential mcqs class 12 are widely used to reinforce learning through application-based thinking.

The standard electrode potential mcqs class 12 refers to the potential difference developed between an electrode and the electrolyte when both are in their standard states. Standard conditions include a temperature of 298 K, pressure of 1 atm for gases, and concentration of 1 molar for aqueous solutions. All standard electrode potentials are measured relative to the standard hydrogen electrode (SHE), which is assigned a potential value of 0.00 V. Understanding this reference point is fundamental when practicing standard electrode potential mcqs class 12.

Standard electrode potential values help predict the direction of electron flow in an electrochemical cell. An electrode with a higher (more positive) standard reduction potential tends to gain electrons more readily and acts as a cathode, while one with a lower (more negative) potential loses electrons and acts as an anode. This concept is repeatedly tested in standard electrode potential mcqs class 12, especially in questions related to spontaneous and non-spontaneous reactions.

Another important application of standard electrode potential is determining the emf (electromotive force) of a cell. The cell emf is calculated using the difference between the standard electrode potentials of the cathode and anode. Mastery of this calculation is essential, as standard electrode potential mcqs class 12 frequently involve numerical evaluation of cell emf using tabulated values.

Standard electrode potential values also allow comparison of oxidising and reducing strengths. A species with a higher standard reduction potential is a stronger oxidising agent, while one with a more negative potential is a stronger reducing agent. This ranking principle is central to redox chemistry and is a recurring theme in standard electrode potential mcqs class 12.

Temperature, concentration, and pressure can alter electrode potential under non-standard conditions, which leads to the application of the Nernst equation. However, the foundation for applying the Nernst equation always begins with standard electrode potential data. Many standard electrode potential mcqs class 12 indirectly test this conceptual link without explicitly mentioning the equation.

In corrosion science, standard electrode potential helps explain why certain metals corrode more easily than others. Metals with highly negative standard electrode potentials, such as zinc and iron, oxidise readily and are more prone to corrosion. This real-world relevance makes standard electrode potential mcqs class 12 particularly important for conceptual clarity beyond rote learning.

Electrolytic and galvanic cells both rely on standard electrode potential values for predicting feasibility. In galvanic cells, reactions occur spontaneously due to favourable electrode potentials, whereas in electrolytic cells, external energy is required. Questions testing this distinction often appear in standard electrode potential mcqs class 12.

The role of standard electrode potential is also significant in electrolysis, electroplating, and electrorefining processes. Selection of suitable electrodes and prediction of deposition order are directly based on electrode potential values, another reason why standard electrode potential mcqs class 12 remain a high-weightage topic.

From an examination perspective, students who repeatedly practice standard electrode potential mcqs class 12 develop faster analytical skills, better interpretation of electrochemical data, and improved numerical accuracy. These advantages are crucial for scoring well in Class 12 board exams as well as entrance examinations.

Standard Electrode Potential MCQs Class 12 with Answers

 1.

For the cell Ag(s) | Ag⁺(aq) || Cu²⁺(aq) | Cu(s), the reduction potentials of the left and right hand electrodes are 0.337 and 0.799 volts, the cell e.m.f. is
a) 0.426 V
b) 0.462 V
c) −0.462 V
d) −1.36 V
Answer: b

2.

Given ECr3+/Cr0=−0.72 VE^0_{Cr^{3+}/Cr} = -0.72\,VECr3+/Cr0​=−0.72V, EFe2+/Fe0=−0.42 VE^0_{Fe^{2+}/Fe} = -0.42\,VEFe2+/Fe0​=−0.42V.
The potential for the cell Cr | Cr³⁺ (0.1 M) || Fe²⁺ (0.01 M) | Fe is
a) −0.26 V
b) 0.399 V
c) 0.462 V
d) 0.26 V
Answer: d

3.

The EM3+/M2+0E^0_{M^{3+}/M^{2+}}EM3+/M2+0​ values for Cr, Mn, Fe and Co are −0.41, +1.57, +0.77 and +1.97 V respectively. For which metal is +2 → +3 oxidation easiest?
a) Cr
b) Mn
c) Fe
d) Co
Answer: a

4.

At 298 K, the emf of the cell
Ag(s) | Ag⁺(0.1 M) || Zn²⁺(0.1 M) | Zn(s)
(Given Ecell0=−1.562VE^0_{cell} = -1.562 VEcell0​=−1.562V) is
a) 1.532 V
b) −3.06 V
c) 3.06 V
d) −1.532 V
Answer: d

5.

A hydrogen electrode is immersed in a solution of pH = 0. Potential change after adding equivalent NaOH is
a) increase by 0.41 V
b) increase by 59 mV
c) decrease by 0.41 V
d) decrease by 59 mV
Answer: c

6.

Standard electrode potential for
Fe³⁺ + e⁻ → Fe²⁺ is
a) 0.772 V
b) −0.404 V
c) −0.772 V
d) −0.036 V
Answer: a

7.

Pressure of H₂ required to make hydrogen electrode emf zero in pure water at 25°C is
a) 10⁻⁷ atm
b) 10⁻¹⁴ atm
c) 0.5 atm
d) 1 atm
Answer: b

8.

Standard emf of spontaneous cell formed by Zn and Ni is
a) 1.01 V
b) −0.51 V
c) 0.51 V
d) −1.01 V
Answer: c

9.

EMnO4−/MnO20E^0_{MnO_4^-/MnO_2}EMnO4−​/MnO2​0​ equals
a) 1.70 V
b) 1.37 V
c) 0.51 V
d) 0.48 V
Answer: a

10.

Incorrect statement regarding redox titration of Fe²⁺ is
a) MnO₄⁻ can be used in aqueous HCl
b) Cr₂O₇²⁻ can be used in aqueous HCl
c) Cr₂O₇²⁻ can be used in aqueous H₂SO₄
d) MnO₄⁻ can be used in aqueous H₂SO₄
Answer: a

11.

Cell EMF for given half reactions is
a) −0.3125 V
b) 0.3125 V
c) 1.14 V
d) −1.14 V
Answer: b

12.

Electrolysis of CuSO₄ using copper electrodes: Assertion–Reason
a) Both correct, reason correct
b) Both correct, reason incorrect
c) Assertion correct, reason incorrect
d) Both incorrect
Answer: a

13.

Correct order of metal deposition at cathode is
a) A, B, C, D
b) A, B, C
c) D, C, B, A
d) C, B, A
Answer: b

14.

E° for reaction 3Mn²⁺ → Mn + 2Mn³⁺ is
a) −2.69 V (not possible)
b) −2.69 V (possible)
c) −3.33 V (not possible)
d) −3.33 V (possible)
Answer: a

15.

Equilibrium constant for Zn | Zn²⁺ || Fe²⁺ | Fe is
a) 100.32/0.059110^{0.32/0.0591}100.32/0.0591
b) 100.32/0.029510^{0.32/0.0295}100.32/0.0295
c) 100.26/0.029510^{0.26/0.0295}100.26/0.0295
d) 100.32/0.29510^{0.32/0.295}100.32/0.295
Answer: b

16.

E° of H₂–O₂ fuel cell at 298 K is
a) 2.48 V
b) 1.24 V
c) 2.5 V
d) 1.26 V
Answer: b

17.

Potential change of Cu²⁺|Cu on 100× dilution is
a) +120 mV
b) −120 mV
c) +60 mV
d) −60 mV
Answer: d

18.

Effect of doubling Cu²⁺ on E°cell is
a) Doubled
b) Halved
c) Increased slightly
d) Decreases slightly
Answer: d

19.

E° for disproportionation of Cu⁺ is
a) −0.38 V
b) 0.49 V
c) −0.49 V
d) 0.38 V
Answer: d

20.

Solution giving H₂ at cathode and O₂ at anode is
a) Molten NaCl
b) Conc. NaCl
c) Dilute NaCl
d) Solid NaCl
Answer: c

21.

Electrolytic refining of copper uses
a) Cu–Ni electrodes
b) Pure Cu anode
c) Graphite cathode
d) Impure Cu anode & pure Cu cathode
Answer: d

22.

Standard oxidation potential of Zn is
a) 0.76 V
b) −0.76 V
c) 2.36 V
d) −2.36 V
Answer: a

23.

Least stable oxide is
a) Ag₂O
b) Al₂O₃
c) MgO
d) Na₂O
Answer: a

24.

Main function of salt bridge is
a) Ion migration
b) Linking half cells
c) Electrical neutrality
d) None
Answer: c

25.

Oxidation potential of hydrogen electrode at pH = 10 is
a) 0.118 V
b) 1.18 V
c) 0.059 V
d) 0.59 V
Answer: d

26.

E° and feasibility of 3Mn²⁺ → Mn + 2Mn³⁺
a) −4.18 V, yes
b) −2.69 V, yes
c) −2.69 V, no
d) 2.69 V, no
Answer: c

27.

H₂ liberated at both electrodes except in
a) NaCl
b) NaH
c) LiH
d) HCOONa
Answer: a

28.

Volume of H₂ corresponding to 4.5 g Al deposition is
a) 44.8 L
b) 22.4 L
c) 11.2 L
d) 5.6 L
Answer: d

29.

Strongest oxidising agent is
a) Cl
b) Cr³⁺
c) Mn²⁺
d) MnO₄⁻
Answer: d

Conclusion on Standard Electrode Potential MCQs Class 12

In conclusion, standard electrode potential is not just a theoretical concept but a powerful predictive tool in electrochemistry. A thorough understanding, supported by consistent practice of standard electrode potential mcqs class 12, enables aspirants to confidently tackle numerical problems, conceptual questions, and real-world applications. For any Class 12 chemistry student, mastering this topic is a decisive step toward electrochemistry excellence—and that is exactly why standard electrode potential mcqs class 12 form an indispensable part of exam preparation.