Class 12 chemistry MCQs with correct option and explanation. These MCQs are based on the CBSE board Class 12 chemistry syllabus. with the help of these Multiple choice questions, students will be able to quickly review topics covered and prepare for the Class 12 board exam as well as other entrance exams such as NEET and JEE.
Class 12 Electrochemistry MCQs
Q.1: Which of the following is not a conductor of electricity?
(a) Copper
(b) Silver
(c) Pure water
(d) Graphite
Q.2: In a galvanic cell, the anode is the electrode where:
(a) Reduction takes place
(b) Oxidation takes place
(c) Electrons are gained
(d) None of the above
Q.3: The standard reduction potential of a half-cell is measured under standard conditions of:
(a) 1 atm pressure
(b) 298 K temperature
(c) 1 M concentration
(d) All of the above
Q.4: The unit of cell constant is:
(a) S cm
(b) cm⁻¹
(c) ohm cm
(d) ohm cm⁻¹
Q.5: Which of the following statements is true for a galvanic cell?
(a) Anode is positively charged
(b) Cathode is negatively charged
(c) Anode is negatively charged
(d) Electrons flow from cathode to anode
Q.6: The molar conductivity of a solution:
(a) Increases with dilution
(b) Decreases with dilution
(c) Remains constant
(d) None of the above
Q.7: The electrochemical equivalent of a substance is:
(a) Directly proportional to its molar mass
(b) Inversely proportional to its molar mass
(c) Directly proportional to its equivalent mass
(d) Inversely proportional to its equivalent mass
Q.8: Faraday’s first law of electrolysis states that:
(a) The mass of a substance deposited is proportional to the current
(b) The mass of a substance deposited is proportional to the charge
(c) The mass of a substance deposited is proportional to the time
(d) None of the above
Q.9: The Nernst equation for the cell potential is given by:
(a) E = E⁰ – (0.059/n) log Q
(b) E = E⁰ + (0.059/n) log Q
(c) E = E⁰ – (RT/nF) ln Q
(d) E = E⁰ + (RT/nF) ln Q
Q.10: In the electrolysis of aqueous NaCl, the product at the cathode is:
(a) Cl₂
(b) H₂
(c) Na
(d) O₂
Q.11: The electrolysis of molten NaCl produces:
(a) Na at the cathode and Cl₂ at the anode
(b) Na at the anode and Cl₂ at the cathode
(c) H₂ at the cathode and O₂ at the anode
(d) H₂ at the anode and O₂ at the cathode
Q.12: Which of the following metals cannot be obtained by electrolysis of its aqueous salt solution?
(a) Cu
(b) Zn
(c) Na
(d) Ag
Q.13: The standard electrode potential of Zn²⁺/Zn is -0.76 V. What does this indicate?
(a) Zinc is a strong oxidizing agent
(b) Zinc is a strong reducing agent
(c) Zinc cannot be oxidized
(d) Zinc has a low tendency to get reduced
Q.14: The product formed at the anode during the electrolysis of dilute sulfuric acid is:
(a) H₂
(b) O₂
(c) SO₂
(d) H₂SO₄
Q.15: Conductance of a solution is inversely proportional to:
(a) Resistance
(b) Specific conductance
(c) Cell constant
(d) Equivalent conductance
Q.16: Which of the following is a primary cell?
(a) Lead-acid battery
(b) Nickel-cadmium battery
(c) Dry cell
(d) Lithium-ion battery
Q.17: The amount of electricity required to deposit 1 mole of a substance is:
(a) 1 Faraday
(b) 1 Coulomb
(c) 96500 Coulombs
(d) 96500 Faradays
Q.18: The electrode at which reduction occurs is called:
(a) Anode
(b) Cathode
(c) Electrolyte
(d) None of the above
Q.19: The salt bridge in an electrochemical cell is used to:
(a) Complete the circuit
(b) Prevent the mixing of solutions
(c) Maintain electrical neutrality
(d) All of the above
Q.20: Which of the following statements is true about electrolysis?
(a) It involves the transfer of electrons
(b) It involves the transfer of ions
(c) It is a spontaneous process
(d) None of the above
Q.21: In the electrolysis of aqueous copper sulfate using copper electrodes, the mass of the anode:
(a) Increases
(b) Decreases
(c) Remains the same
(d) None of the above
Q.22: The electrode potential of a half-cell depends on:
(a) Temperature
(b) Concentration of ions
(c) Nature of the electrode
(d) All of the above
Q.23: The standard hydrogen electrode is assigned a potential of:
(a) 0.00 V
(b) 1.00 V
(c) 0.059 V
(d) -0.059 V
Q.24: During the electrolysis of water, the volume of hydrogen gas collected at the cathode is:
(a) Equal to the volume of oxygen gas collected at the anode
(b) Half of the volume of oxygen gas collected at the anode
(c) Twice the volume of oxygen gas collected at the anode
(d) None of the above
Q.25: The electrochemical series is useful for predicting:
(a) Cell potential
(b) Direction of electron flow
(c) Feasibility of redox reactions
(d) All of the above
Q.26: In a concentration cell, the electrode with higher concentration acts as:
(a) Anode
(b) Cathode
(c) Electrolyte
(d) None of the above
Q.27: The pH of a solution can be determined using:
(a) Hydrogen electrode
(b) Glass electrode
(c) Calomel electrode
(d) All of the above
Q.28: The equivalent conductance of a strong electrolyte:
(a) Increases with dilution
(b) Decreases with dilution
(c) Remains constant with dilution
(d) None of the above
Q.29: The emf of a cell can be measured using:
(a) Voltmeter
(b) Ammeter
(c) Potentiometer
(d) Galvanometer
Q.30: The spontaneous reaction in a galvanic cell occurs because:
(a) ΔG is positive
(b) ΔG is negative
(c) ΔH is positive
(d) ΔH is negative
Q.31: In an electrolytic cell, the direction of electron flow is:
(a) From anode to cathode
(b) From cathode to anode
(c) Depends on the electrolyte
(d) Depends on the applied voltage
Q.32: In the Nernst equation, E = E° – (RT/nF) ln Q, the term Q represents:
(a) Reaction quotient
(b) Heat evolved
(c) Concentration of reactants
(d) Number of electrons
Q.33: The standard cell potential (E°cell) is calculated using:
(a) E°cell = E°cathode + E°anode
(b) E°cell = E°cathode – E°anode
(c) E°cell = E°anode – E°cathode
(d) E°cell = E°anode + E°cathode
Q.34: A Faraday is equal to:
(a) 1 Coulomb
(b) 96500 Coulombs
(c) 1 mole of electrons
(d) Both (b) and (c)
Q.35: During electrolysis, the amount of substance deposited at an electrode is proportional to:
(a) Current
(b) Time
(c) Both (a) and (b)
(d) Voltage
Q.36: The role of a salt bridge in a galvanic cell is to:
(a) Transfer electrons
(b) Complete the circuit
(c) Measure emf
(d) Provide ions for the reaction
Q.37: Which of the following is not a standard condition for measuring electrode potentials?
(a) 1 M concentration
(b) 298 K temperature
(c) 1 atm pressure
(d) 25°C temperature
Q.38: The oxidation number of chlorine in NaClO₃ is:
(a) +1
(b) +3
(c) +5
(d) +7
Q.39: The electrolysis of an aqueous solution of KCl produces:
(a) K at the cathode and Cl₂ at the anode
(b) H₂ at the cathode and Cl₂ at the anode
(c) K at the cathode and O₂ at the anode
(d) H₂ at the cathode and O₂ at the anode
Q.40: In the context of galvanic cells, the term ‘EMF’ stands for:
(a) Electromagnetic Field
(b) Electromotive Force
(c) Electrostatic Force
(d) Electrolytic Mobility
Q.41: The conductivity of an electrolyte depends on:
(a) Nature of the electrolyte
(b) Concentration of the electrolyte
(c) Temperature
(d) All of the above
Q.42: The product formed at the cathode during the electrolysis of molten MgCl₂ is:
(a) Mg
(b) Cl₂
(c) H₂
(d) O₂
Q.43: Which of the following is true for a galvanic cell under standard conditions?
(a) ΔG = 0
(b) ΔG > 0
(c) ΔG < 0
(d) ΔG is independent of the reaction
Q.44: Which metal is used as a reference electrode?
(a) Zinc
(b) Copper
(c) Platinum
(d) Silver
Q.45: The relationship between Gibbs free energy and the electromotive force of a cell is given by:
(a) ΔG = -nFE
(b) ΔG = nFE
(c) ΔG = nF/E
(d) ΔG = -E/nF
Q.46: In electroplating, the object to be plated is made the:
(a) Anode
(b) Cathode
(c) Electrolyte
(d) None of the above
Q.47: The unit of molar conductivity is:
(a) S cm
(b) S cm² mol⁻¹
(c) S cm mol⁻¹
(d) S cm⁻¹ mol
Q.48: The process of corrosion of iron is essentially an electrochemical process involving:
(a) Oxidation of iron at the anode
(b) Reduction of oxygen at the cathode
(c) Both (a) and (b)
(d) None of the above
Q.49: Which electrolyte is commonly used in a dry cell battery?
(a) NaCl
(b) KOH
(c) NH₄Cl
(d) H₂SO₄
Q.50: The electrochemical equivalent of a substance is:
(a) Its equivalent weight divided by Faraday’s constant
(b) Its molecular weight divided by Faraday’s constant
(c) Its atomic weight divided by Faraday’s constant
(d) Its valence divided by Faraday’s constant