Electrolysis Quiz

1. Which of the following correctly identifies the electrodes and electrolyte in an electrolytic cell?

• A. Anode is positive, cathode is negative, electrolyte is the molten or aqueous ionic compound
• B. Anode is negative, cathode is positive, electrolyte is the external circuit
• C. Anode is positive, cathode is positive, electrolyte is the wire connecting the electrodes
• D. Anode is negative, cathode is negative, electrolyte is the power supply

2. During the electrolysis of molten lead(II) bromide using inert electrodes, what products are formed?

• A. Bromine gas at cathode; lead metal at anode
• B. Lead metal at cathode; bromine gas at anode
• C. Lead oxide at cathode; bromine gas at anode
• D. Hydrogen gas at cathode; bromine gas at anode

3. When electroplating is carried out, which statement is correct about the electrodes used?

• A. Both electrodes must be inert materials such as carbon
• B. The object being plated is the anode, and the plating metal is the cathode
• C. The object being plated is the cathode, and the plating metal is the anode
• D. Both electrodes must be made from the same metal as the plating metal

4. During the electrolysis of concentrated aqueous sodium chloride solution using inert electrodes, chloride ions are preferentially discharged at the anode instead of hydroxide ions. What is the main reason for this?

• A. Chloride ions have a lower charge density than hydroxide ions
• B. Chloride ions are present in much higher concentration than hydroxide ions
• C. Hydroxide ions are too small to be oxidised at the anode
• D. Chloride ions are easier to oxidise because they have a higher electronegativity

5. During the electrolysis of aqueous copper(II) sulfate using copper electrodes, copper metal forms at the cathode. Which ionic half-equation correctly represents this reduction process?

• A. Cu → Cu²⁺ + 2e⁻
• B. Cu²⁺ + 2e⁻ → Cu
• C. Cu²⁺ + 2e⁻ → Cu⁺
• D. Cu + 2e⁻ → Cu²⁻