The _________ provides reactants for the cathodic reaction and allows the flow of ions.

• A. Electrolytes
• B. Electrodes
• C. Anodes
• D. Separator

Answer: (A)

The electrolyte is the ion-conducting medium that provides the ions required for the cathodic reduction and allows ions to move between the electrodes to complete the circuit. In corrosion and electrochemistry, the cathodic reaction needs species in solution to be reduced, and these species are supplied by the ions present in the electrolyte. As electrons flow through the external circuit to the cathode, ions migrate to balance charge, keeping the process continuous. The separator merely blocks direct contact between electrodes while still allowing ion movement, and the electrodes themselves are sites for electron transfer rather than sources of the cathodic reactants. Anodes are where oxidation occurs, not where cathodic reactants come from.