Electrolysis | Definition, Uses, & Facts (2024)

chemical reaction

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Last Updated: May 24, 2024•Article History

Key People:: Michael Faraday; Sir Humphry Davy; Johann Wilhelm Ritter; William Nicholson

Related Topics:: electricity; Faraday’s laws of electrolysis; ion; migration; migration velocity

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electrolysis, process by which electric current is passed through a substance to effect a chemical change. The chemical change is one in which the substance loses or gains an electron (oxidation or reduction). The process is carried out in an electrolytic cell, an apparatus consisting of positive and negative electrodes held apart and dipped into a solution containing positively and negatively charged ions. The substance to be transformed may form the electrode, may constitute the solution, or may be dissolved in the solution. Electric current (i.e., electrons) enters through the negatively charged electrode (cathode); components of the solution travel to this electrode, combine with the electrons, and are transformed (reduced). The products can be neutral elements or new molecules. Components of the solution also travel to the other electrode (anode), give up their electrons, and are transformed (oxidized) to neutral elements or new molecules. If the substance to be transformed is the electrode, the reaction is often one in which the electrode dissolves by giving up electrons.

Electrolysis is used extensively in metallurgical processes, such as in extraction (electrowinning) or purification (electrorefining) of metals from ores or compounds and in deposition of metals from solution (electroplating). Metallic sodium and chlorine gas are produced by the electrolysis of molten sodium chloride; electrolysis of an aqueous solution of sodium chloride yields sodium hydroxide and chlorine gas. Hydrogen and oxygen are produced by the electrolysis of water.

Electrolysis | Definition, Uses, & Facts (1)

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The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Adam Augustyn.

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Electrolysis | Definition, Uses, & Facts? ›

The use of electric current to stimulate a non-spontaneous reaction

spontaneous reaction
A spontaneous reaction is a reaction that favors the formation of products at the conditions under which the reaction is occurring. A roaring bonfire is an example of a spontaneous reaction, since it is exothermic (there is a decrease in the energy of the system as energy is released to the surroundings as heat).
https://chem.libretexts.org › 20:_Entropy_and_Free_Energy
20.3: Spontaneous and Nonspontaneous Reactions

. Electrolysis can be used to separate a substance into its original components/elements and it was through this process that a number of elements have been discovered and are still produced in today's industry.

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What are the uses of electrolysis? ›

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What are the important facts about electrolysis? ›

Electrolysis is the passing of a direct electric current through an electrolyte which is producing chemical reactions at the electrodes and decomposition of the materials. The main components required to achieve electrolysis are an electrolyte, electrodes, and an external power source.

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What are some examples of electrolysis? ›

A familiar example of electrolysis is recharging a battery, which involves use of an external power source to drive the spontaneous (discharge) cell reaction in the reverse direction, restoring to some extent the composition of the half-cells and the voltage of the battery.

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Where electrolysis is useful in the real world? ›

It is used in the extraction of metals from their ores like Aluminium and Potassium. It is used in refining the metals like Copper and Zinc. It is also used in the electroplating of Gold and Silver.

What else can electrolysis be used for? ›

Electrolysis can be used to purify metals or extract them from a solution or break down substances into their individual components. For example, a sodium chloride solution can be turned into chlorine gas and sodium hydroxide, while the electrolysis of water produces hydrogen gas and oxygen.

How is electrolysis useful to humans? ›

What is the advantage of electrolysis? Many people experience permanent hair removal after finishing electrolysis treatments. Also, electrolysis works with the widest range of skin and hair types. It's good for sensitive areas of the body, like the face or bikini line.

How painful is electrolysis? ›

You'll feel a sharp sting or temporary warmth as each hair follicle is treated. How much the process hurts depends on how you react to pain and the area being treated.

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Why is electrolysis needed? ›

Electrolysis gives us a means to reduce metals that we would otherwise be incapable of producing. For example, electrolysis of aluminium means we can have aluminium products. Such lightweight materials are important for a whole variety of reasons, from drinking cans to aircraft.

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What are the reasons for using electrolysis? ›

The purpose of using electrolysis in metal extraction is to separate metal ions from a solution or molten substance and deposit them as pure metal at the electrodes. Electrolysis is particularly useful for extracting metals that cannot be obtained through reduction or smelting, such as aluminum and magnesium.

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How is electrolysis used today? ›

Electrolysis is one of those processes which are widely used in the metal industry. Whether it's the extraction of metals from their ores, purification of metals, or electroplating of metals; all these applications involve electrolysis. Moreover, it is extensively used for manufacturing industrial chemicals like brine.

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What are the 3 products of electrolysis? ›

Electrolysis is a very commercial and important process to produce Hydrogen gas, Chlorine gas and Sodium Hydroxide.

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What products use electrolysis? ›

Using electrolysis to produce chlorine from the sodium chloride in brine (salt water) also produces sodium hydroxide (alkali) and hydrogen. These chemicals are used to manufacture soaps, textiles, pharmaceuticals, plastics, and many other products.

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What is a main benefit of electrolysis? ›

Electrolysis Is the Key to Permanent Hair Removal

There are many ways to remove unwanted body or facial hair. Shaving, plucking, and body waxing all are options, but unfortunately, they provide only temporary results. For those who are seeking a permanent way to remove body hair, electrolysis is an attractive option.

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Which technology uses electrolysis? ›

There are three main types of electrolyzers in water electrolysis hydrogen production process technology: alkaline electrolytic cells, polymer electrolytic cells, and solid oxide electrolytic cells. Among them, alkaline electrolytic cells are the earliest commercially available electrolytic cell technologies.