Lesson 14.2.1

14.2.1 Storage cells and hydrogen-oxygen fuel cells Quiz: Pearson Edexcel Chemistry, Unit 14

20 questions

In partnership with Revision Ninja

Lesson 14.2.1, Storage cells and hydrogen-oxygen fuel cells: 20 multiple choice questions for the Pearson Edexcel Chemistry (9CH0), Unit 14: Redox II, written with Revision Ninja.

Host it live on the board and students join with a game code on their own devices, or revise alone with Free Play. The answers are revealed in the game.

Host this setFree Play

The 20 questions

  1. What is a storage cell?

    • A cell that can be recharged by reversing the cell reaction with an external electrical supply
    • A cell that cannot be recharged and releases its stored energy only once, then must be discarded
    • A cell that produces hydrogen gas as its only product, which is then stored for later use
    • A cell that stores electrons permanently in an electrode, so that no chemical reaction takes place
  2. What are the electrodes and electrolyte of a lead-acid storage cell?

    • Nickel and cadmium electrodes in aqueous potassium hydroxide
    • Lead and lead(IV) oxide electrodes in sulfuric acid
    • Hydrogen and oxygen electrodes in phosphoric acid
    • Zinc and manganese dioxide electrodes in potassium hydroxide
  3. What happens to the sulfuric acid concentration of a lead-acid cell during discharge?

    • It decreases, because sulfate is used up as lead(II) sulfate forms
    • It increases, because lead(II) sulfate dissolves in the acid
    • It increases, because water is consumed in the reaction
    • It remains exactly unchanged throughout discharge
  4. What is a fuel cell?

    • A cell whose electrodes are consumed and must be replaced regularly, with the fuel supply stopped
    • A cell in which a fuel and oxygen react continuously, converting chemical energy directly into electrical energy
    • A cell that uses only solar energy to split water into hydrogen and oxygen gases at the anode
    • A cell that stores electricity from a mains supply as chemical energy and releases it on demand
  5. What is the only product of a hydrogen-oxygen fuel cell in its overall reaction?

    • Ammonia
    • Hydrogen peroxide
    • Carbon dioxide
    • Water
  6. What is the anode reaction of a hydrogen-oxygen fuel cell with an acidic electrolyte?

    • 2H+ + 2e- gives H2
    • H2O gives O2 + 4H+ + 4e-
    • O2 + 4H+ + 4e- gives 2H2O
    • H2 gives 2H+ + 2e-
  7. What is the approximate emf of one lead-acid cell?

    • About 2.0 V
    • About 1.2 V
    • About 4.5 V
    • About 0.8 V
  8. What is the cathode reaction in an acidic hydrogen-oxygen fuel cell?

    • H2 gives 2H+ + 2e-
    • O2 + 4H+ + 4e- gives 2H2O
    • 2H2O gives O2 + 4H+ + 4e-
    • O2 + 2H2O + 4e- gives 4OH-
  9. What is the anode reaction in an alkaline hydrogen-oxygen fuel cell?

    • 2H+ + 2e- gives H2
    • O2 + 2H2O + 4e- gives 4OH-
    • H2 + 2OH- gives 2H2O + 2e-
    • H2O + e- gives OH- + H
  10. What is the theoretical emf of a hydrogen-oxygen fuel cell at standard conditions?

    • 2.46 V
    • 1.23 V
    • 0.00 V
    • -1.23 V
  11. Which of these is a hydrogen-rich fuel used in fuel cells?

    • Methanol, CH3OH
    • Nitrogen gas
    • Argon
    • Neon
  12. During recharging of a lead-acid cell, which electrode acts as the cathode?

    • The sulfuric acid, which is reduced to hydrogen
    • The lead(IV) oxide electrode, where Pb is reduced
    • The lead electrode, where PbSO4 is reduced back to Pb
    • Both electrodes act as anodes during charging
  13. Why can a fuel cell be more efficient than a combustion engine?

    • It burns the fuel at a higher temperature than a combustion engine, which gives a greater power output
    • It converts chemical energy directly to electrical energy without the heat step limited by the Carnot cycle
    • It produces more heat than a combustion engine from the same fuel, which is then used to drive the cell
    • Combustion engines do not produce any useful energy from the fuels they burn in normal operation
  14. In an acidic hydrogen-oxygen fuel cell, which way do electrons flow?

    • From the oxygen electrode to the hydrogen electrode through the external circuit, against the flow of protons
    • From the hydrogen (anode) electrode through the external circuit to the oxygen (cathode) electrode
    • Electrons do not move at all, because only the H+ ions carry the current through the electrolyte
    • Through the electrolyte from the cathode to the anode, carried by the mobile hydrogen ions
  15. Using E-zero(O2/OH-) = +0.40 V and E-zero(H2O/H2) = -0.83 V, what is the emf of an alkaline hydrogen-oxygen fuel cell?

    • -0.43 V
    • +1.23 V
    • +2.46 V
    • +0.43 V
  16. How many moles of electrons are transferred per mole of H2 and per mole of O2 in the fuel cell?

    • 2 mol per mole of H2 and 2 mol per mole of O2
    • 2 mol per mole of H2 and 4 mol per mole of O2
    • 1 mol per mole of H2 and 2 mol per mole of O2
    • 4 mol per mole of H2 and 2 mol per mole of O2
  17. Which statement about the lead-acid storage cell is correct?

    • Its theoretical emf is 0 V, so it can only store energy and never deliver a usable voltage
    • It has no electrolyte, so the cell never needs replacing and the electrodes do not change at all
    • It is not rechargeable and produces hydrogen gas at the anode, which is then released from the cell
    • It is rechargeable, but its electrodes are consumed and the electrolyte is depleted during discharge
  18. A student says hydrogen fuel cells produce no pollution at the point of use. Which evaluation is best?

    • True, because they also release no heat at all, so the cell is completely clean and efficient
    • Largely true at the point of use, because the only product is water, although hydrogen production may emit CO2
    • False, because they emit carbon dioxide as the main product, which is released directly from the fuel cell
    • False, because they produce ammonia as the main product, which is released into the air at the cathode
  19. What is the overall reaction of a hydrogen-oxygen fuel cell?

    • 2H2O gives 2H2 + O2
    • H2 + O2 gives H2O2
    • H2 + O2 gives 2OH-
    • 2H2 + O2 gives 2H2O
  20. How many moles of electrons flow through the external circuit when 2.0 mol of H2 is consumed in a hydrogen-oxygen fuel cell?

    • 8.0 mol
    • 4.0 mol
    • 1.0 mol
    • 2.0 mol

All Pearson Edexcel Chemistry quizzes