Electric Cell
Definition and meaning of Electric Cell in chemistry.
An electric cell is a device that changes chemical energy directly into electrical energy. It does this through a spontaneous chemical reaction called a redox reaction. This process creates a steady flow of electrons through an external wire.
In more detail
Every electric cell has two solid pieces called electrodes sitting in a special liquid. This liquid is called an electrolyte and it contains dissolved mobile ions. One electrode is the anode, where the chemical reaction releases free electrons.
The other electrode is the cathode, which gladly accepts these traveling electrons. A wire connects the two electrodes outside the cell to carry the current. Meanwhile, ions move through the liquid electrolyte to balance the shifting electrical charges.
This continuous flow of particles creates a specific voltage known as electromotive force. Chemistry students often use the word battery when they actually mean a single cell. A true battery is simply two or more electric cells physically linked together.
Chemists split all electric cells into two main groups based on their lifespan. Primary cells become completely dead once their starting chemical ingredients run out. Secondary cells are rechargeable because you can force the internal chemical reaction backward. You just plug them into a charger to push electrons the opposite way.
Key facts
| Field | Physical Chemistry |
|---|---|
| Device Function | Converts chemical energy to electrical energy |
| Key Components | Anode, cathode, and liquid electrolyte |
| Anode Reaction | Releases electrons (oxidation) |
| Cathode Reaction | Accepts electrons (reduction) |
| Cell Categories | Primary (single-use) and secondary (rechargeable) |
The historic Daniell cell places a zinc metal anode into a zinc sulfate solution. It connects to a copper metal cathode sitting in a copper sulfate solution. The zinc naturally breaks down to release electrons and form positive Zn2+ ions. These electrons travel through a wire to turn Cu2+ ions into solid copper metal. This specific chemical setup produces a reliable standard voltage of about 1.10 volts. Early telegraph systems relied heavily on these specific cells for long-distance electrical communication.
Frequently asked questions
What is the actual difference between an electric cell and a battery?
An electric cell is a single unit that produces a specific voltage. A battery is a connected group of multiple cells working together to provide more power.
Can you recharge every type of electric cell?
No. Primary cells use irreversible chemical reactions and must be thrown away. You can only recharge secondary cells, like the ones in your mobile phone.
Which way do the electrons flow in a standard electric cell?
Electrons always flow out from the negative anode and travel through the external wire. They eventually arrive at the positive cathode to complete the chemical reaction.