1. What is an electrochemical cell?
- a) A device that converts chemical energy into electrical energy
- b) A device that converts electrical energy into mechanical energy
- c) A device that converts mechanical energy into chemical energy
- d) A device that converts heat energy into chemical energy
Answer: a) A device that converts chemical energy into electrical energy
Explanation: Electrochemical cells use chemical reactions to generate electricity.
2. In an electrochemical cell, the anode is where:
- a) Oxidation takes place
- b) Reduction takes place
- c) Electrons are consumed
- d) Protons are produced
Answer: a) Oxidation takes place
Explanation: In an electrochemical cell, oxidation occurs at the anode.
3. Which of the following is NOT a type of electrochemical cell?
- a) Galvanic (Voltaic) cell
- b) Electrolytic cell
- c) Fuel cell
- d) Nuclear cell
Answer: d) Nuclear cell
Explanation: Galvanic, electrolytic, and fuel cells are all types of electrochemical cells, while nuclear cells are unrelated to electrochemistry.
4. The electrode where reduction occurs is called:
- a) Cathode
- b) Anode
- c) Salt bridge
- d) Electrolyte
Answer: a) Cathode
Explanation: Reduction takes place at the cathode in both galvanic and electrolytic cells.
5. In a galvanic cell, the direction of electron flow is:
- a) From anode to cathode
- b) From cathode to anode
- c) In both directions
- d) None of the above
Answer: a) From anode to cathode
Explanation: Electrons always flow from the anode (where oxidation occurs) to the cathode (where reduction occurs) in a galvanic cell.
6. In an electrolytic cell, the anode is:
- a) Positive
- b) Negative
- c) Neutral
- d) Depends on the electrolyte
Answer: a) Positive
Explanation: In electrolytic cells, the anode is positive because an external power source forces the oxidation reaction at this electrode.
7. Which of the following components is necessary in a galvanic cell to complete the circuit?
- a) Salt bridge
- b) Diode
- c) Resistor
- d) Capacitor
Answer: a) Salt bridge
Explanation: The salt bridge allows the flow of ions to maintain electrical neutrality in the cell, ensuring continuous electron flow through the external circuit.
8. The function of a salt bridge in an electrochemical cell is to:
- a) Transfer electrons
- b) Provide ionic contact between the two half-cells
- c) Maintain the pH of the solution
- d) Provide a solid medium for the reaction
Answer: b) Provide ionic contact between the two half-cells
Explanation: A salt bridge helps to maintain charge balance by allowing ions to flow between the two solutions in a galvanic cell.
9. In a galvanic cell, the cell potential is positive when:
- a) The cell is operating spontaneously
- b) The cell is in equilibrium
- c) The external power source is switched off
- d) The concentrations of electrolytes are equal
Answer: a) The cell is operating spontaneously
Explanation: A positive cell potential indicates that the galvanic cell is spontaneous, meaning the reaction is favorable and electricity is generated.
10. Which of the following best describes a standard hydrogen electrode (SHE)?
- a) It is used as a reference electrode with a potential of 1V
- b) It has a standard electrode potential of 0V
- c) It acts as the cathode in all electrochemical cells
- d) It is composed of a copper wire immersed in hydrogen gas
Answer: b) It has a standard electrode potential of 0V
Explanation: The standard hydrogen electrode (SHE) is defined as having an electrode potential of 0V, and is used as a reference point to measure other electrode potentials.
Leave a comment