Explain why the anode of an electrolytic cell is positive even though oxidation occurs there. Include in your answer the role of the external power source and the direction of electron flow.
Answer
In an electrolytic cell, the external power source supplies electrons to the cathode and pulls electrons from the anode, making the anode positive. This forces oxidation at the anode and reduction at the cathode.
Step-by-step solution
- State that an electrolytic cell uses an external power supply to drive a non‑spontaneous reaction.
- Explain that the power supply forces electrons to flow from the anode (connected to the positive terminal) to the cathode (negative terminal).
- Clarify that electrons are removed from the anode, creating a deficit of negative charge, which makes the anode positively charged.
- Describe that oxidation occurs at the anode because atoms lose electrons, which are pulled away by the positive terminal of the supply.
- Mention that reduction occurs at the cathode where electrons are supplied by the negative terminal.
- Summarize that the positive charge of the anode is a result of the external electric field, not the oxidation process itself.
Common mistake: Thinking the anode is positive because oxidation releases electrons, not because of the external power
Concept tested: Electrolytic cell operation
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