Answer: Concentrations of the same electrolyte differ in the two half-cells.
- A Two electrodes of different standard reduction potential are used
- B Concentrations of the same electrolyte differ in the two half-cells
- C A temperature gradient is imposed across the salt bridge
- D An external EMF source drives the current
Correct answer: B. Concentrations of the same electrolyte differ in the two half-cells
Explanation: In a concentration cell, both electrodes are identical but placed in solutions of different concentrations. The EMF arises from this difference.
In a Daniell cell, electrons flow externally from the zinc anode (oxidation) through the voltmeter to the copper cathode (reduction), while the salt bridge completes the circuit.
Concept context
Explore the link between chemical reactions and electricity. Covers galvanic cells, electrolysis, standard electrode potentials, the Nernst equation, and real-world applications like batteries and corrosion.