An electrode is a substance that helps to conduct electricity by establishing electrical contact with non-metallic parts of the circuit.
The substance provides a medium where electric currents enter and leave the non-metallic parts like an electrolyte cell.
The main components of an electrode are cathode and anode. These components help to describe the flow of current within a circuit.
So, what is the main difference between anode and cathode? The former is a terminal where the conventional current flows into a device from outside while the latter is the terminal where the conventional current flows out of the device.
However, these components can be interchanged during a reversible process. To clear out the confusion, this article provides further differences between anode and cathode.
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Comparison Table (Anode vs Cathode)
Basic Terms | Anode | Cathode |
Description | It is an electrode that carries conventional current from the positive terminal to the negative terminal. | It is an electrode that carries electrical current from the negative terminal to the positive terminal. |
Symbol Representation |
+ |
– |
Alternative Name | Positive Charge/ Electron Donor. | Negative Charge/ Electron acceptor. |
Type of Reaction | Oxidation reactions occur at the anode. | Reduction reaction occurs at the cathode. |
Concentration in Electrolyte Cell | Excess positive charge. | Excess negative charge. |
Galvanic Cell | Become a negative charge in a galvanic or voltaic cells. | Become positive charge in a galvanic or voltaic cell. |
Current Flow | Flows from the outside into the device. | Flows out of the device. |
Attraction | Attracts negative charges or anions. | Attracts positive cations and rejects negatively charged anions. |
Redox Reaction | Oxidation takes place. | Reduction takes place. |
What Happens During Charging | Creation of electrons | Consumption of electrons. |
What Is an Anode?
It is a type of electrode that is either positive or negative depending on the type of cell. But anode is defined as a positively charged terminal where current flows into the device.
An anode in electrochemistry is a terminal where oxidation or loss of electrons occurs. The negative anions usually react to give off electrons.
The anode is a negative terminal in a galvanic cell and electrons move towards the external part of the circuit. The anode is a positive terminal in an electrolyte cell.
What Is A Cathode?
It is a type of electrode that holds positive or negative polarity depending on the type of cell. It is also a terminal where a reduction process or gain of electrons takes place.
A cathode terminal is negative since the electrical energy generated results in the decomposition of chemical compounds. The terminal is positive in the galvanic cell since chemical reactions result in electrical energy.
Cathode electrodes are classified as hot and cold cathodes. A hot cathode is the one heated in presence of a filament to emit electrons by thermionic emission.
Cold cathodes are not heated by any filament. The cathode is also flagged cold when it emits more electrons when compared to the hot counterpart.
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Main Differences between Anode and Cathode
- The anode is the terminal where electricity enters the device. The cathode is the terminal where electricity leaves the device.
- The anode is the positive terminal. The cathode is the negative terminal.
- Oxidation occurs at the anode in an electrolyte cell. Reduction takes place at the cathode in an electrolyte cell.
- Anode becomes cathode in a galvanic cell. Cathode becomes an anode in a galvanic cell.
- Anode attracts electrons or anions. Cathode attracts cations or positive charges.
Frequently Asked Questions
Is the Cathode Positive or Negative?
The positive is the anode and the negative a cathode during the charge. The positive is the cathode and the negative is anode during the discharge.
Is Anode Always Positive?
Not really. It depends on the type of cell. The anode is negative and the cathode is positive in a galvanic or voltaic cell. The anode is positive and cathode negative in an electrolyte cell.
Why Anode Is Negative?
The anode is negative in an electrochemical cell due to the negative potential with respect to the solution. The anode is positive in an electrolyte cell since it is connected to the positive terminal of the battery.
Is Copper an Anode or Cathode?
Zinc usually behaves like an anode in a galvanic cell and copper as a cathode. The zinc electrode is known for supply electrons and copper for consuming electrons.
Does the Anode Lose Mass?
Absolutely. The anode is a reducing agent which causes the reduction of ions at the cathode. The mass will reduce since the reacting anode becomes aqueous. The mass of the cathode will increase as the aqueous ions turn to solid.
Why Is Anode Positive in Gel Electrophoresis?
Gel electrophoresis is a process where molecules are separated based on size and charge. The anode is the positive pole and the cathode is the negative pole. The charged particles usually migrate to the positive nodes during the gel electrophoresis method.
Does Current Flow from Anode to Cathode?
Absolutely. The electrons flow from anode to cathode and anions flow from cathode to anode. It makes the current flow from anode to cathode.
Does Anode Gain Mass During Discharge?
Yes. A reduction process takes place at the cathode. It implies that the anode will gain mass during the discharge operation.
Are Batteries Galvanic or Electrolytic?
Most rechargeable batteries are electrolytic while those being used in a device have a galvanic cell function. Galvanic batteries use redox energy to produce electricity.
Are Galvanic Cells Rechargeable?
The salt bridge allows the flow of ions from the cathode to the anode. The ion flow is usually spontaneously making the galvanic cell either rechargeable or non-rechargeable.
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In Conclusion
The main difference between anode and cathode is that anode is a positively charged terminal while the cathode is a negatively charged terminal. But this depends on the type of cell.
According to an experiment, electrolyte cells experience current flow from anode to cathode, and galvanic cells’ current flows from cathode to anode.
More Sources and References
- https://www.biologic.net/topics/anode-cathode-positive-and-negative-battery-basics/
- https://en.wikipedia.org/wiki/Anode
- https://depts.washington.edu/matseed/batteries/MSE/components.html
- https://www.qrg.northwestern.edu/projects/vss/docs/power/2-how-do-batteries-work.html
- https://www.britannica.com/technology/anode