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 28 of 35
- A. -2
- B. -4
- C. -5
- D. -1
Explanation: as K belongs to group 1A so it has 1 oxidation number which is why Oxygen will also have one oxidation number, but in negative.
Correct answer: -1- A. Yellow to blue
- B. Orange to yellow
- C. Yellow to orange
- D. Green to yellow
Explanation: Potassium dichromate is a powerful oxidizing agent, and its color changes depending on its oxidation state.
Correct answer: Orange to yellow- A. Cu (Copper)
- B. Ag (Silver)
- C. Pt (Platinum)
- D. None
Explanation: Platinum is often used as an inert electrode because it doesn't undergo significant chemical reactions during electrochemical processes.
Correct answer: Pt (Platinum)- A. N (Nitrogen)
- B. Cr (Chromium)
- C. S (Sulfur)
- D. Mn (Manganese)
Explanation: Manganese (Mn) exhibits a wide range of oxidation states, including +2, +4, +6, and +7.
Correct answer: Mn (Manganese)- A. The flow of electrons takes place from copper to zinc
- B. Eoredof copper electrode is less than that of zinc electrode
- C. Zinc acts as an anode and copper as cathode
- D. All are correct
Explanation: Anode: The electrode where oxidation occurs (loss of electrons). Zinc is more readily oxidized than copper, meaning it loses electrons…
Correct answer: Zinc acts as an anode and copper as cathode- A. IM ZnO solution
- B. 1M ZnSO4 solution
- C. I.5M ZnSO4 solution
- D. 0.IM ZnSO4 solution
Explanation: Standard electrode potential is measured in a half-cell containing the metal (Zn) in contact with a solution of its ions (ZnSO4) at 1M…
Correct answer: 1M ZnSO4 solution- A. Electrons
- B. Current
- C. anions
- D. ions
Explanation: While some anions might migrate through the salt bridge, a mixture of cation and anion movement is necessary for proper circuit completion.
Correct answer: ions- A. by addition of fresh solution
- B. replacing external circuit with external source of electricity
- C. by removal of solution
- D. by heating it
Explanation: Voltaic cells, also known as galvanic cells, convert chemical energy into electrical energy.
Correct answer: replacing external circuit with external source of electricity- A. to form positive ions
- B. to form negative tons
- C. gain electrons
- D. all are possible
Explanation: A higher standard reduction potential indicates a greater tendency for a species to gain electrons and be reduced.
Correct answer: to form positive ions550. Secondary cell is
- A. rechargeable
- B. Non-rechargeable
- C. Electrolytic cells
- D. Daniel cell
Explanation: Secondary cells, also known as rechargeable batteries, can be restored to their original state by reversing the discharge process through…
Correct answer: rechargeable- A. 1.5 volts
- B. 2 volts
- C. 3 volts
- D. 1 volt
Explanation: The capacity of a lead accumulator cell can be expressed in both Ampere-hours (Ah) or Watt-hours (Wh) and volts,depending on the context.
Correct answer: 2 volts- A. MnO₂
- B. Zn (Zinc)
- C. AgO₂ (Silver oxide)
- D. Cadmium
Explanation: Anode vs Cathode: In a battery, the anode is the negative electrode where oxidation occurs (loss of electrons).
Correct answer: Zn (Zinc)- A. Gain of electrons
- B. Loss of electrons
- C. Gain of hydrogen
- D. Addition of electrons
Explanation: Oxidation = loss of electrons (OIL). Reduction = gain of electrons (RIG).
Correct answer: Loss of electrons- A. Sodium
- B. Magnesium
- C. Aluminum
- D. lron
Explanation: Option A) Sodium is not obtained by electrolysis of fused bauxite. Sodium is usually obtained by the electrolysis of molten sodium…
Correct answer: Aluminum- A. Bromine is reduced and water is oxidized.
- B. Bromine is both reduced and oxidized.
- C. Bromine is oxidized and carbonate is reduced.
- D. Bromine is neither reduced nor oxidized.
Explanation: The correct answer is that bromine is both reduced and oxidized. This reaction is an example of a disproportionation reaction.
Correct answer: Bromine is both reduced and oxidized.- A. Oxidation-Reduction (Redox) Reaction
- B. Addition Reaction
- C. Substitution Reaction
- D. Autoxidation Reaction
- E. Reduction Reaction
Explanation: The correct answer is a substitution reaction. In the reaction CH3Cl + Cl2 → CH2Cl2 + HCl, a chlorine atom substitutes a hydrogen atom in…
Correct answer: Substitution Reaction- A. Electrons on the left-hand side only.
- B. Electrons on the right-hand side only.
- C. Electrons on Either the left or right-hand side.
- D. None of these.
Explanation: In the ion-electron method, each half-reaction is balanced by ensuring that the number of electrons is the same on both sides of the…
Correct answer: Electrons on Either the left or right-hand side.- A. 2 atm
- B. 780 mmHg
- C. 19 Psi
- D. 1 atm
Explanation: When hydrogen gas bubbles into a one molar solution of HCl, it is usually assumed to be at standard conditions unless otherwise specified.
Correct answer: 1 atm- A. Copper Sulfate
- B. Copper Chloride
- C. Zinc Chloride
- D. Zinc Sulfate
Explanation: In a voltaic cell, the zinc electrode is typically immersed in a zinc sulfate (ZnSO4) solution, which serves as the electrolyte.
Correct answer: Zinc Sulfate- A. Potential energy
- B. Chemical energy
- C. Kinetic energy
- D. Free Electrons
Explanation: A voltaic cell produces electrical energy from chemical energy. This type of electrochemical cell utilizes spontaneous redox reactions to…
Correct answer: Chemical energy