| Feature | Galvanic (Voltaic) Cell | Electrolytic Cell |
|---|---|---|
| Spontaneity | Spontaneous ( < 0) | Non-spontaneous ( > 0) |
| E°cell | Positive (>0) | Negative (requires external EMF) |
| Energy conversion | Chemical → Electrical | Electrical → Chemical |
| Anode polarity | NEGATIVE (−) | POSITIVE (+) |
| Cathode polarity | POSITIVE (+) | NEGATIVE (−) |
| Anode reaction | Oxidation | Oxidation |
| Cathode reaction | Reduction | Reduction |
| Salt bridge | Required (present) | Not needed (single container) |
| External circuit | Electrons flow from anode to cathode | External battery drives electrons to cathode |
| Electrolyte flow | Ions maintain neutrality via salt bridge | Ions carry current within the solution |
| Example | Daniell cell (Zn/Cu) | Electrolysis of NaCl, electroplating |
Critical NEET Trap
"AN OX RED CAT" rule holds for BOTH cell types:
- Anode = Oxidation (always, in any electrochemical cell)
- Cathode = Reduction (always, in any electrochemical cell)
ONLY the polarity flips:
- Galvanic anode = negative (electrons leave spontaneously)
- Electrolytic anode = positive (external battery forces electrons in)