Electrochemistry Quiz

Duration: 45 Minutes Total Marks: 30

Section A: Multiple Choice (5 Marks)

  1. In an electrolytic cell, the electrode where oxidation occurs is the:
    A. Cathode (negative)
    B. Cathode (positive)
    C. Anode (negative)
    D. Anode (positive)

  2. What is the observation at the anode during the electrolysis of molten lead(II) bromide ($\text{PbBr}_2$)?
    A. Grey metallic deposit
    B. Colorless bubbles of gas
    C. Reddish-brown fumes
    D. Pale green gas

  3. Which of the following is correct for the electrolysis of concentrated aqueous sodium chloride ($\text{NaCl}$)?
    A. Sodium metal forms at the cathode.
    B. Hydrogen gas forms at the cathode.
    C. Oxygen gas forms at the anode.
    D. Chlorine gas forms at the cathode.

  4. To silver-plate a copper spoon, the spoon should be connected to:
    A. The anode
    B. The cathode
    C. A salt bridge
    D. An inert graphite electrode

  5. Which statement about hydrogen-oxygen fuel cells is correct?
    A. They produce $\text{CO}_2$ as a byproduct.
    B. The only product of the reaction is water.
    C. They are less efficient than gasoline engines.
    D. They require the combustion of hydrogen in air.

Section B: Short Answer (15 Marks)

  1. Describe the process of electroplating a piece of steel with copper. Include the identity of the anode, cathode, and the electrolyte used. (5 Marks)

  2. State two advantages of using a hydrogen-oxygen fuel cell instead of a gasoline engine. (4 Marks)

  3. Predict the products formed at the cathode and anode during the electrolysis of:
    a) Molten potassium fluoride ($\text{KF}$) (2 Marks)
    b) Dilute aqueous sodium chloride ($\text{NaCl}$) (4 Marks)

Section C: Extended Response (10 Marks)

  1. Aqueous copper(II) sulfate ($\text{CuSO}_4$) is electrolyzed using copper electrodes.

    a) Write the ionic half-equation for the reaction occurring at the cathode. (2 Marks)
    b) Write the ionic half-equation for the reaction occurring at the anode. (2 Marks)
    c) Describe what happens to the mass of the anode and the cathode over time. Explain your answer. (4 Marks)
    d) Contrast this with the result if graphite (inert) electrodes were used instead of copper electrodes at the anode. (2 Marks)

Attempt the quiz before checking the mark scheme
Mark Scheme C4 - Electrochemistry Mark Scheme
Topic guide: C4 - Electrochemistry