Understanding the Difference between Electrolytic Cell and Galvanic Cell
When it comes to the mechanisms that produce electrical energy, two important types of cells are the electrolytic cell and the galvanic cell. Both these cells involve the transfer of electrons between two electrodes, but they operate differently and serve different purposes. In this article, we will explain the key differences between these two types of cells.
What is an Electrolytic Cell?
An electrolytic cell is an electrochemical cell where non-spontaneous redox reactions take place by the application of an external electrical energy. In other words, the cell uses electrical energy to drive a chemical reaction that would not occur spontaneously. An electrolytic cell contains an external power source (like a battery) and two electrodes, known as cathode and anode, that are immersed in an electrolytic solution.
The anode is positively charged, and the cathode is negatively charged. When a voltage is applied across these two electrodes, electrons flow from the anode to the cathode, and the anode undergoes an oxidation reaction, while the cathode undergoes a reduction reaction. An electrolytic cell can be used for a variety of purposes, including electroplating, metal refining, and the production of chemicals.
What is a Galvanic Cell?
A galvanic cell, also known as a voltaic cell, is an electrochemical cell where spontaneous redox reactions take place, producing electrical energy. It contains two half-cells, each consisting of an electrode and an electrolytic solution. The two half-cells are connected through a salt bridge or a porous membrane that allows the flow of ions but prevents the mixing of the electrolytes.
The electrode in one half-cell acts as the anode, while the electrode in the other half-cell acts as the cathode. Oxidation occurs at the anode, where electrons are released into the electrolytic solution. Reduction occurs at the cathode, where electrons from the anode are taken up. The electrons flow from the anode to the cathode through an external circuit, producing the electrical energy.
Galvanic cells are commonly used in batteries that power a range of devices, from flashlights to cars. They can also be used in fuel cells, where the chemical energy of a fuel is converted directly into electrical energy.
The Key Differences
The main difference between electrolytic cells and galvanic cells is that electrolytic cells require an external source of electrical energy, while galvanic cells produce electrical energy spontaneously. Electrolytic cells are used for non-spontaneous reactions (like in electroplating), while galvanic cells are used for spontaneous reactions (like in batteries).
Another important difference is that in electrolytic cells, the anode is negatively charged, while in galvanic cells, the anode is positively charged. This is because in electrolytic cells, the external power source is driving the reaction, so the electrons flow from the cathode to the anode. In galvanic cells, the spontaneous reaction causes electrons to flow from the anode to the cathode.
Conclusion
Both electrolytic cells and galvanic cells play a crucial role in the production and use of electrical energy. While they share some similarities, they operate differently and serve different purposes. Understanding the difference between these two types of cells is essential for anyone interested in electrochemistry and energy production.
Table difference between electrolytic cell and galvanic cell
Here is an example HTML code to create a table comparing electrolytic cells and galvanic cells:
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| Cell Type | Operates with | Electrodes | Direction of electron flow | Reaction at anode | Reaction at cathode | Energy source |
|---|---|---|---|---|---|---|
| Electrolytic cell | External electrical source | Positive (anode) and negative (cathode) | Opposite to external circuit | Oxidation (loses electrons) | Reduction (gains electrons) | External electrical source |
| Galvanic cell | Spontaneous redox reaction | Oxidation (anode) and reduction (cathode) | Along the external circuit | Oxidation (loses electrons) | Reduction (gains electrons) | Chemical energy from reactants |
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This code will create a table with 7 columns, including the cell type, the way it operates, the type of electrodes it uses, the direction of electron flow, the reaction at the anode and cathode, and the energy source. The table will have two rows for the two types of cells being compared: electrolytic cells and galvanic cells. The table will also have a header row (thead) and a body (tbody) for the content.
The resulting table will look like this:
| Cell Type | Operates with | Electrodes | Direction of electron flow | Reaction at anode | Reaction at cathode | Energy source |
| — | — | — | — | — | — | — |
| Electrolytic cell | External electrical source | Positive (anode) and negative (cathode) | Opposite to external circuit | Oxidation (loses electrons) | Reduction (gains electrons) | External electrical source |
| Galvanic cell | Spontaneous redox reaction | Oxidation (anode) and reduction (cathode) | Along the external circuit | Oxidation (loses electrons) | Reduction (gains electrons) | Chemical energy from reactants |