1. The diagram below shows the electrolysis of concentrated aqueous potassium chloride using platinum electrodes. Which of the following statements is TRUE regarding the electrolysis of concentrated aqueous potassium chloride?

• H₂O is reduced at the cathode due to its more negative E⁰ value than K⁺.
• Cl⁻ is oxidised at the anode due to its more positive E⁰ value than H₂O.
• Cl⁻ ions are oxidised at anode due to higher concentration.
• Platinum is an active electrode.

2. The standard reduction electrode potential for several half-reactions at 298 K are shown below. Which of the following species is the strongest oxidising agent?

• X⁻

• Y³⁺

• Z

• X₂

Answer explanation

strongest oxidising agent -> undergo reduction (gain electron, +SRP value) -> species who gain electron (look at reactant side)

3. According to Faraday's first law, the amount of a substance produced at each electrode in an electrolytic cell is directly proportional to the

• voltage provided
• quantity of electricity passed
• temperature
• concentration of electrolyte

4. What are the features of a standard hydrogen electrode?

I. Hydrogen gas at 1 atm and 298 K

II. A platinum electrode

III. A carbon electrode

IV. 1M aqueous solution of a strong acid

• I, II and III
• I, II and IV
• II, III and IV
• I, II, III and IV

5. The following diagram shows a galvanic cell. Which of the following statements is correct?

• The aluminium electrode is cathode.
• The mass of Pb plate decreases.
• Pb (lead) reduces.
• Aluminium electrode is the negative terminal.

6. 2Ag⁺ (aq) + Mg (s) ⟶ 2Ag (s) + Mg²⁺ (aq)

Calculate E° cell.

[Given E° Ag⁺/Ag = +0.80V and E° Mg²⁺/Mg= - 2.36V ]

• -1.56 V
• -3.16V
• +1.56 V
• +3.16V

7. Explain why a salt bridge is usually necessary for the operation of a galvanic cell

I. To allow the electron to flow from anode to cathode.

II. To complete the circuit

III. To maintain the electrical neutrality of both electrolytes.

• I only
• I and II
• II and III
• I, II and III

8. Standard hydrogen electrode operated under standard conditions of 1 atm H₂ pressure, 25°C, and pH = 0 has a cell potential of

• 0.00 V
• 0.05 V
• 0.10 V
• 0.50 V

9. Electrochemistry is the study of production of electricity from

• nuclear energy and the use of heat energy to bring about non-spontaneous chemical transformations.
• energy released during spontaneous chemical reactions and the use of electrical energy to bring about non-spontaneous chemical transformations.
• nuclear energy and the use of electrical energy to bring about non-spontaneous chemical transformations.
• energy released during spontaneous chemical reactions and the use of heat energy to bring about non-spontaneous chemical transformations.

10. The Nernst equation is used to calculate the cell potential of a galvanic cell under non-standard conditions. Which is the correct expression of Nernst equation for the following reaction? Ni (s) + Cl₂ (g) ⟶ Ni²⁺ (aq) + 2Cl (aq)⁻

• A
• B
• C
• D