Answer: maintain electrical neutrality.
- A directly supply the electrons
- B maintain electrical neutrality
- C greatly speed the reaction
- D give colour to the solution
Correct answer: B. maintain electrical neutrality
Explanation: The salt bridge completes the circuit and keeps both half-cells electrically neutral as ions are used up.
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.