Electrochemistry Quiz

Grade 11 · Science · Quiz

10 questions covering oxidation-reduction, galvanic cells, electrolysis, standard potentials, and Faraday's Laws.

Questions

1. What does 'oxidation' mean in terms of electrons?

   1. Gain of electrons
   2. Loss of electrons
   3. Transfer of protons
   4. Addition of oxygen only
   Show answer

   Answer: Loss of electrons

   OIL — Oxidation Is Loss (of electrons). The oxidation number increases when electrons are lost.

2. In a galvanic cell, at which electrode does reduction occur?

   1. Anode
   2. Cathode
   3. Salt bridge
   4. Both electrodes equally
   Show answer

   Answer: Cathode

   RIG — Reduction Is Gain. Electrons flow from anode to cathode; at the cathode they are gained by the oxidizing agent.

3. Calculate E°cell: E°cathode = +1.36 V, E°anode = +0.34 V.

   1. +1.70 V
   2. +1.02 V
   3. +0.68 V
   4. −1.02 V
   Show answer

   Answer: +1.02 V

   E°cell = E°cathode − E°anode = 1.36 − 0.34 = +1.02 V.

4. What indicates a spontaneous electrochemical reaction?

   1. Negative E°cell
   2. Zero E°cell
   3. Positive E°cell
   4. High temperature only
   Show answer

   Answer: Positive E°cell

   A positive E°cell corresponds to a negative ΔG (ΔG = −nFE°cell), confirming the reaction is thermodynamically spontaneous.

5. What process occurs at the anode during electrolysis?

   1. Reduction
   2. Deposition of metal
   3. Oxidation
   4. Proton transfer
   Show answer

   Answer: Oxidation

   Oxidation always occurs at the anode — in electrolytic cells the anode is connected to the positive terminal, attracting anions that lose electrons.

6. In Zn + CuSO₄ → ZnSO₄ + Cu, copper is:

   1. Oxidized and is the reducing agent
   2. Reduced and is the oxidizing agent
   3. Oxidized and is the oxidizing agent
   4. Neither oxidized nor reduced
   Show answer

   Answer: Reduced and is the oxidizing agent

   Cu²⁺ gains 2 electrons → Cu (reduction). By accepting electrons, Cu²⁺ oxidizes zinc — making it the oxidizing agent.

7. Electroplating uses which type of cell?

   1. Galvanic cell
   2. Fuel cell
   3. Electrolytic cell
   4. Concentration cell
   Show answer

   Answer: Electrolytic cell

   Electroplating is a nonspontaneous process requiring electrical energy — it uses an electrolytic cell with the object to be plated as the cathode.

8. Faraday's Laws of electrolysis state that the mass of substance deposited is proportional to:

   1. Voltage applied
   2. Temperature of the solution
   3. Charge passed (current × time)
   4. Concentration of electrolyte
   Show answer

   Answer: Charge passed (current × time)

   Q = It (charge = current × time). Mass deposited ∝ Q ∝ moles of electrons transferred.

9. The standard hydrogen electrode (SHE) has a standard reduction potential of:

   1. +1.00 V
   2. +0.50 V
   3. 0.00 V
   4. −1.00 V
   Show answer

   Answer: 0.00 V

   The SHE (2H⁺ + 2e⁻ → H₂) is assigned exactly 0.00 V and serves as the universal reference for all standard reduction potentials.

10. Zinc coated on steel (galvanizing) prevents rusting because:

    1. Zinc blocks oxygen from reaching the steel
    2. Zinc has a lower reduction potential than iron and preferentially oxidizes
    3. Zinc is nonreactive with water
    4. Zinc acts as a cathode
    Show answer

    Answer: Zinc has a lower reduction potential than iron and preferentially oxidizes

    Zinc (E° = −0.76 V) is more easily oxidized than iron (E° = −0.44 V). It acts as a sacrificial anode, corroding in place of the steel.

Get a personalized course on Electrochemistry built around your child.