Answer:
A battery that produces electricity
Step-by-step explanation:
Galvanic cell is a battery which converts chemical energy to electrical energy.
In galvanic cell two half cells work, one is cathodic and other is anodic.
At cathode reduction takes place and at anode oxidation takes place.
Due to this redox reaction some voltage is generated which is known as emf of the cell.
The EMF of the cell calculated from the difference of reduction potential of cathode and anode.
The cell will work if the emf of the cell is positive.
If emf of the cell is positive it means that cell is spontaneous,
Free energy change = ΔG°= -nFE°
thus a positive values of E° corresponds to negative value of ΔG°, and hence a spontaneous reaction.
Where E° is emf of the cell