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 35 of 35
- A. Cathode
- B. Anode
- C. External conductor
- D. Cathode and anode
Explanation: In a Galvanic cell, the redox reaction occurs at two different electrodes, the cathode, and the anode.
Correct answer: Anode- A. that is required for the preparation of bleaching powder
- B. site free when excess of sulphuric acid is added to the bleaching powder
- C. that is required for the generation of hypochlorine
- D. Both B and C
Explanation: The bleaching action of bleaching powder is due to the release of "available chlorine" when it comes into contact with an acidic…
Correct answer: that is required for the generation of hypochlorine- A. Zn + Cu2+ → Zn2+ + Cu
- B. Zn2+ + Cu → Cu2+ + Zn
- C. 2 Fe(OH)3 → 2 Fe + 3/2 O2 + 3 H2O
- D. 2NaCl → 2Na + Cl2
Explanation: A spontaneous chemical reaction is one that occurs without continuous external energy input, often characterized by a negative Gibbs free…
Correct answer: Zn + Cu2+ → Zn2+ + Cu684. Which of the following titrants would most likely be used as ths' own indicator in acid medium?
- A. K2Cr2O7 (Potassium dichromate)
- B. Iodine (I2)
- C. KMnO4 (Potassium permanganate)
- D. H2O2 (Hydrogen peroxide)
Explanation: Potassium permanganate (KMnO4) is used as its own indicator because it changes color distinctly at the endpoint of a titration in an…
Correct answer: KMnO4 (Potassium permanganate)- A. Cu only
- B. Zn only
- C. Cu & Ni only
- D. Ni and Zn only
Explanation: The correct answer is Zn only. Zinc has a standard reduction potential of -0.76 V, which is more negative than iron's -0.41 V.
Correct answer: Zn only- A. Pb is converted to PbO2
- B. PbSO4 is converted to Ph
- C. Pb is converted to PbSO4
- D. None of the above
Explanation: Pb oxidized to PBSO4When the battery is discharging, it acts as a galvanic cell and the following chemical reaction occurs:Negative:Pb(s)…
Correct answer: Pb is converted to PbSO4- A. Lead
- B. Lead oxide
- C. Lead hydroxide
- D. None of the above
Explanation: In a lead storage battery, the cathode is made up of lead dioxide, alternatively we can also use lead oxide as it is still an oxide of…
Correct answer: Lead oxide- A. Chloride is oxidized and sodium is reduced
- B. Chlorine acts as an oxidizing agent and sodium as a reducing agent
- C. Chlorine acts as a reducing agent
- D. None of the above
Explanation: In the reaction 2Na(s) + Cl2(g) ⟶ 2NaCl(s), sodium (Na) is oxidized to Na+, losing electrons, and thus acts as the reducing agent.
Correct answer: Chlorine acts as an oxidizing agent and sodium as a reducing agent689. If one Faraday was to be 30,230 coulombs instead of 96,500 coulombs then charge on an electron is:
- A. 1.5 x 10^-19C
- B. 1 x 10^-19C
- C. 0.5 x 10^-19C
- D. 6.02 x 10^-19C
Explanation: The correct answer is 0.5 x 10-19C. A Faraday represents the total charge of one mole of electrons.
Correct answer: 0.5 x 10^-19C- A. Zn + Cu²+ → Zn²+ + Cu
- B. Fe + H2O → Fe2+ + OH-
- C. 2H2 + O2 → 2H2O
- D. Ag+ + Cl- → AgCl
Explanation: The correct answer is the reaction Zn + Cu²+ → Zn²+ + Cu. This reaction is spontaneous because it has a positive standard cell potential…
Correct answer: Zn + Cu²+ → Zn²+ + Cu- A. Corrosion cannot be eliminated completely
- B. Employing modern techniques corrosion can be completely eliminates.
- C. Corrosion process can be slowed down by certain methods.
- D. The presence of acidic oxide in the environment can accelerate the process of corrosion.
Explanation: Option B is correct as corrosion can be eliminated using modern techniques
Correct answer: Employing modern techniques corrosion can be completely eliminates.- A. BO2-
- B. SnO32
- C. S2O34-
- D. MnO42-
Explanation: It is a fact and has to be learntThe correct answer is D) MnO42-.MnO42- is unstable in solution because it can disproportionate to form…
Correct answer: MnO42-- A. Cathode rays
- B. X rays
- C. Anode rays
- D. All of the above
Explanation: cathode rays are not directly related to reducing effects. Cathode rays are streams of electrons that are emitted from the cathode…
Correct answer: Cathode rays- A. Oxidizing agent
- B. Reducing agent
- C. Bleaching agent
- D. Dehydrating agent
Explanation: Potassium dichromate (K2Cr2O7) is a strong oxidizing agent. It readily accepts electrons from other substances, causing them to be…
Correct answer: Oxidizing agent- A. The size of the electrode
- B. The pH of the solution
- C. The amount of metal in the anode
- D. The values of the half cell
Explanation: For a galvanic cell, emf can be calculated by standard reduction potentials for two half cells.
Correct answer: The values of the half cell- A. Standard Hydrogen Electrode SHE always acts as anode
- B. SHE may act as cathode or anode depending upon the reduction potential of the counterpart
- C. SHE always acts as cathode in voltaic cell
- D. None of the above
Explanation: SHE may act as cathode or anode depending upon the reduction potential of the counterpart: This statement is correct.
Correct answer: SHE may act as cathode or anode depending upon the reduction potential of the counterpart