We have learnt that there are two types of cells namely electrochemical cells and electrolytic cells. Electrochemical cell is a device which converts chemical energy into electrical energy. On the other hand, electrolytic cell is a device which converts electrical energy into chemical energy. The two cells also differ significantly with respect to the charges on the electrodes. For example, in electrochemical cell anode is negative whereas in electrolytic cell, the anode is positive. Similarly, cathode is positive in electrochemical cell whereas it is negative in the electrolytic cell. The main points of difference have been summed up as follows in Table 34.1.
1. Differences between Galvanic Cell and Electrolytic Cell
1. In galvanic cell, electrical energy is produced.
2. In galvanic cell, reaction taking place is spontaneous.
3. The two half cells are set up in different containers and are connected through salt
bridge or porous partition.
4. In galvanic cell, anode is negative and cathode is positive.
5. The electrons move from anode to cathode in external circuit.
1. In electrolytic cell, electrical energy is consumed.
2. In electrolytic cell, reaction taking place is nonspontaneous.
3. Both the electrodes are placed in the solution or molten electrolyte in the same container.
4. In electrolytic cell, the anode is positive and cathode is negative.
5. The electrons are supplied by the external source. They enter through cathode and come out through anode.