Free Electrochemistry MCQs with Answers
696 Electrochemistry MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Electrochemistry describes electron transfer through oxidation and reduction, identifies oxidizing and reducing agents, and applies oxidation numbers to balance redox equations. It also covers electrode potential and the standard hydrogen electrode, which provides the reference for comparing the reduction tendencies of other electrodes.
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Read the Electrochemistry notesFree MDCAT chapter notes with key terms696 questions · page 25 of 35
- A. The smaller the E°red, the greater the reducing power of a metal
- B. E°red of Li+ is minimum (-3.04V)
- C. The greater the E°red, the greater the oxidizing power of a non-metal
- D. E°red of Cl2 is maximum (+2.87V)
Explanation: The correct answer is Option D. The statement that E°red of Cl2 is maximum (+2.87V) is incorrect because the maximum standard reduction…
Correct answer: E°red of Cl2 is maximum (+2.87V)- A. It is used as a reference electrode
- B. Its E°red is zero or less than zero
- C. When it is connected to a zinc electrode in a galvanic cell, it acts as the cathode
- D. When it is connected to a copper electrode in a galvanic cell, it acts as an anode
Explanation: The correct answer is Option B. The standard reduction potential of the standard hydrogen electrode is defined to be exactly 0 volts.
Correct answer: Its E°red is zero or less than zero- A. +1.10 volts
- B. -0.42 volts
- C. -1.10 volts
- D. +0.42 volts
Explanation: In a Galvanic cell, the cell potential (Ecell) is calculated using the formula:Ecell = E(cathode) - E(anode)For the given reaction, the…
Correct answer: +1.10 volts- A. Every top metal can displace lower one in redox reaction
- B. Every lower non-metal can displace higher one in redox reaction
- C. E°cell =E°oxid + E°red
- D. E°red increases from bottom to top
Explanation: Reduction potential increases from top to bottom.
Correct answer: E°red increases from bottom to top- A. Every top metal acts as anode
- B. Every lower metal acts as cathode
- C. Oxidizing power of an element decreases from top to bottom
- D. Reducing power of an element decreases from top to bottom
Explanation: The correct answer is Option C: 'Oxidizing power of an element decreases from top to bottom.' This statement is incorrect because, in the…
Correct answer: Oxidizing power of an element decreases from top to bottom- A. Na is deposited
- B. O2 gas is released
- C. Neither Na nor H2 is released
- D. H2 gas is released
Explanation: During the electrolysis of an aqueous solution of Na2SO4 using inert electrodes, the cathode reaction involves the reduction of hydrogen…
Correct answer: H2 gas is released- A. H2 gas is released
- B. O2 gas is released
- C. SO2 gas is released
- D. Neither O2 nor SO2 gas is released
Explanation: During the electrolysis of dilute H2SO4 solution with inert electrodes, oxygen gas is released at the anode.
Correct answer: O2 gas is released- A. +5 to +2
- B. +5 to +4
- C. +3 to +2
- D. +4 to +2
Explanation: In the given redox reaction, the nitrogen in nitric acid (HNO3) has an oxidation number of +5.
Correct answer: +5 to +4- A. A
- B. B
- C. C
- D. D
Explanation: The correct answer is Option C. When solid potassium halides react with concentrated sulfuric acid, the oxidation state of sulfur changes…
Correct answer: C- A. Zn
- B. Al
- C. Au
- D. Pb
Explanation: Gold (Au) has a high reduction potential, which means it readily gains electrons and is less likely to oxidize.
Correct answer: Au- A. Hydrolysis
- B. Neutralization
- C. Electrolysis
- D. Galvanizing
Explanation: The correct answer is Electrolysis. This is the process by which an electric current is passed through an electrolyte to cause a chemical…
Correct answer: Electrolysis- A. Nature of electrode and the ions
- B. Concentration of the solution in which the electrode is placed
- C. The temperature of the cell
- D. Surface area of the electrode
Explanation: The correct answer is Surface area of the electrode. The standard electrode potential is a measure of the tendency of a chemical species…
Correct answer: Surface area of the electrode- A. MnO
- B. MnO2
- C. Mn2O3
- D. Mn2O7
Explanation: The compound Mn2O3 is manganese(III) oxide, where manganese has an oxidation state of +3.
Correct answer: Mn2O3- A. Oxidation occurs at anode
- B. Reduction occurs at cathode
- C. Electrons flow from cathode to anode
- D. Both A and B
Explanation: In a galvanic cell, the flow of electrons is from the anode to the cathode through an external circuit.
Correct answer: Electrons flow from cathode to anode- A. Net charge should be the same on each side
- B. Total number of atoms should be the same
- C. Total number of ions should be the same
- D. Both A and B
Explanation: The ion-electron method, also known as the half-reaction method, is a systematic approach to balancing redox reactions.
Correct answer: Both A and B- A. Graphite
- B. Copper
- C. Iron
- D. Inert material
Explanation: In Down's cell, which is employed for the electrolytic production of sodium metal, the cathode is constructed from iron.
Correct answer: Iron- A. Hit and trial method
- B. Inspection method
- C. Identifying the reducing participants
- D. Identifying the oxidized participants
Explanation: The correct answer is the Inspection Method. In the oxidation number method, the final step is to ensure the equation is balanced in terms…
Correct answer: Inspection method- A. Nelson's cell
- B. Down's cell
- C. Nickel cadmium cell
- D. All of these
Explanation: Nelson's cell is specifically designed for the electrolysis of concentrated sodium chloride solution (brine) to produce caustic soda…
Correct answer: Nelson's cell- A. Buffer
- B. Spectator ion
- C. Reaction intermediate
- D. None of these
Explanation: The correct answer is 'Reaction intermediate.' Reaction intermediates are transient species that appear in the steps of a reaction…
Correct answer: Reaction intermediate- A. Oxidation reaction
- B. Addition Reaction
- C. Reduction Reaction
- D. Redox Reaction
Explanation: The correct answer is a Redox Reaction because it involves both oxidation and reduction processes.
Correct answer: Redox Reaction