Difference Between Galvanic Cells and Electrolytic Cells

What are Galvanic Cells?

Galvanic cells consist of two half-cells, which convert the chemical potential energy into electrical potential energy. It happens through a spontaneous chemical reaction.

On the two half-cells of galvanic cells, each half-cell contains an electrode in an electrolyte. The separation is required to prevent a direct chemical contact of the reduction and oxidation reactions by creating a potential difference. Electrons that are released in the oxidation reaction passes through an external circuit before it is being used by the reduction reaction.

Working of Galvanic Cells

It's quite easy to know the working of a galvanic cell. It involves a chemical reaction that allows the electrical energy to use as an end product. During a redox reaction, the galvanic cell uses the energy transfer between electrons to convert chemical energy into electrical energy.

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The galvanic cell has the power to separate the flow of electrons through the cycle of oxidation and reduction, creating a half-reaction and connecting both of them to a wire such that a path may be created for the flow of electrons across that wire. This kind of electron flow is essentially called a current. And, such current can be made to pass through a wire to complete a circuit and to obtain the output in any device like a wristwatch, a television, and so on.

The galvanic cell may be composed of any two metals. If left in contact with each other, these two metals will form an anode and a cathode. This combination makes the galvanic corrosion of the more anodic. A connecting circuit is necessary to prevent this corrosion.

Terms to Remember

A few of the important terms brought into use in galvanic cells are mentioned below.

  •  Phase Boundaries, which refers to two metals acting as a cathode and anode

  • Salt Bridge, a connecting medium that allows a redox reaction to occur

  • Oxidation and reduction, a chemical process which allows the electric current to form and pass through a galvanic cell. 

What are Electrolytic Cells?

Electrolytic cells are much the same as a galvanic cell as it requires a salt bridge, two electrodes in addition to the flow of electrons from the anode to cathode. However, still, the two electrodes manage to differentiate with others in various aspects. For one, the electrolytic cell transforms electrical energy into chemical energy and, not the other way round.

Process of Electrolysis

In simple terms, the process of electrolysis refers to the decomposition of an element that is provided under the influence of an electric current. The first electrolysis was conducted by Sir Humphrey Davey, in 1808. This analysis provided important knowledge into how other elements act and how they vary from compounds and ions.

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The subsequent redox reaction in the process is not natural, so for the start-up reaction, electrical energy must be added into the apparatus. Unlike the galvanic cell, the electrolytic cell requires both metals to be positioned in the same container. In this case, the positive electrode is considered an anode, and the negative electrode is considered a cathode.

What is an Electrochemical Cell?

An electrochemical cell is a device that would generate electrical energy by performing the chemical reactions in it or uses the electrical energy supplied to it, facilitating chemical reactions in it. These devices have the capability to convert electrical energy into chemical energy and vice versa.

A good example of an electrochemical cell is a standard 1.5 Volt battery used to power up many of the electrical devices like a TV remote, a wall clock, and more.

Such types of cells are capable of generating electricity forming the chemical reactions in them are called Galvanic Cells or Voltaic Cells. As an alternative, cells that cause chemical reactions to happen in them when an electrical current is passed through them are referred to as electrolytic cells.

An Illustration of an electrochemical cell is listed below.

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There are numerous differences between galvanic and electrolytic cell to explain. Some of them are tabulated below.

Distinguish Between Electrolytic Cell and Galvanic Cell

Galvanic Cell

Electrolytic Cell

Galvanic cell is an electrochemical cell that can produce electricity using a chemical reaction.

Electrolytic cell uses electric current for the propagation of a chemical reaction.

This cell converts chemical energy into electrical energy.

It converts electrical energy into chemical energy.

Here, a spontaneous reaction occurs.

Here, a nonspontaneous reaction occurs.

Anode is charged negatively, and cathode is charged positively.

Anode is charged positively, and cathode is charged negatively.

Oxidation process takes place at the anode, and the reduction process takes place at the cathode.

Oxidation process takes place at cathode whereas the reduction process takes place at the anode.

Half-cells are placed in different containers and connected through salt bridges.

Electrodes are placed in a similar container in a molten or a solution electrolyte.

Electric energy is generated by undergoing chemical reactions.

Electric energy produces a chemical reaction with the help of an external source.

From the above differences between galvainc and electrolytic cells, we can conclude as a galvanic cell produces electric current with a chemical reaction that happens spontaneously in it, where an electrolytic cell does the opposite. Means, it brings about the chemical reaction using an electric current from an external source.

FAQ (Frequently Asked Questions)

Question: How to Remember What Cathode and Anode Clearly?

Answer: There is, understandably, a lot of confusion that arises on this topic. The cathode or anode is not defined in GENERAL by their respective charges. Because they may have either a positive or negative charge, and it entirely depends on that current situation. Generally, the anode is referred to as an electrode that positive current flows INTO from the outside, and the cathode is referred to as an electrode that it flows FROM (to the outside). Electrons flow the opposite way, anyways.

Electrochemistry states, the anode is where oxidation occurs, and the cathode is where reduction occurs. Besides, anode always attracts negative anions, and cathode attracts positive cations. It happens REGARDLESS of the respective charges on the electrodes themselves.

Also, it is defined by the principal charge of the ENVIRONMENT of the electrode, which is always negative in the case of the cathode due to the reduction taking place and positive at the anode due to oxidation takes place.