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## PowerPedia:Electrolytic

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An electrolyte is a substance containing free There was an error working with the wiki: Code[1] medium. Because they generally consist of ions in solution, electrolytes are also known as ionic solutions, but molten electrolytes and There was an error working with the wiki: Code[2] are also possible. They are sometimes referred to in abbreviated There was an error working with the wiki: Code[40] as lytes.

An electrolytic process is the use of Electrolysis industrially to refine metals or compounds at a high purity and low cost. Some examples are the There was an error working with the wiki: Code[41] used for There was an error working with the wiki: Code[42], or the production of Hydrogen from water. Electrolysis is usually done in bulk using hundreds of sheets of metal connected to an electric power source. These sheets are then lowered into a solution such as copper, the ions from the copper solution get attracted to the positive sheet of metal and forms 99.999% pure copper.

#### Explanation

Electrolytes commonly exist as solutions such as There was an error working with the wiki: Code[3]s or Salts. Furthermore, some Gases may act as electrolytes under conditions of high temperature or low pressure.

Electrolytes are normally formed when a Salt is placed into a There was an error working with the wiki: Code[43] such as Water and the individual atomic components are separated by the force applied upon the There was an error working with the wiki: Code[44] molecule, in a process called There was an error working with the wiki: Code[45] in which the solution applies force to hold the ions apart. Salts are compounds that are linked by weak There was an error working with the wiki: Code[46], and will separate into charged ions in the presence of a solution containing stronger There was an error working with the wiki: Code[47].

An electrolyte may be described as concentrated if it has a high There was an error working with the wiki: Code[4] and There was an error working with the wiki: Code[5] contained within the solution.

#### Physiological importance

In There was an error working with the wiki: Code[48], the primary ions of electrolytes are There was an error working with the wiki: Code[49](Na+), There was an error working with the wiki: Code[50] (K+), There was an error working with the wiki: Code[51] (Ca++), There was an error working with the wiki: Code[52] (Mg++), There was an error working with the wiki: Code[53] (Cl-), There was an error working with the wiki: Code[54] (PO4---), and There was an error working with the wiki: Code[55] (HCO3-). The electric charge symbols of plus (+) and minus (-) are used to indicate that the substance indicated is ionic in nature and has an imbalanced distribution of electrons. This is the result of chemical dissociation.

All higher lifeforms require a subtle and complex electrolyte balance between the There was an error working with the wiki: Code[6]. In particular, the maintenance of precise There was an error working with the wiki: Code[7]s of electrolytes is important. Such gradients affect and regulate the There was an error working with the wiki: Code[56] of the body, There was an error working with the wiki: Code[57] There was an error working with the wiki: Code[58], and are critical for There was an error working with the wiki: Code[59] and There was an error working with the wiki: Code[60] function.

Both muscle tissue and neurons are considered electric tissues of the body. Muscles and neurons are activated by electrolyte activity between the There was an error working with the wiki: Code[61] or interstitial fluid, and There was an error working with the wiki: Code[62]. Electrolytes may enter or leave the cell membrane through specialized protein structures embedded in the There was an error working with the wiki: Code[63] called There was an error working with the wiki: Code[64]. For example, muscle contraction is dependent upon the presence of calcium (Ca++), sodium (Na+), and potassium (K+). (See There was an error working with the wiki: Code[65]) Without sufficient levels of these key electrolytes, muscle weakness or severe muscle contractions may occur.

Electrolyte balance is maintained by oral, or in emergencies, intervenous (IV) intake of electrolyte-containing substances, and is regulated by There was an error working with the wiki: Code[66]s, generally with the There was an error working with the wiki: Code[67]s flushing out excess levels. In humans, electrolyte There was an error working with the wiki: Code[68] is regulated by hormones such as There was an error working with the wiki: Code[69], There was an error working with the wiki: Code[70] and There was an error working with the wiki: Code[71]. Serious There was an error working with the wiki: Code[72]s, such as dehydration and overhydration, may lead to cardiac and neurological complications, and unless they are rapidly resolved will result in a There was an error working with the wiki: Code[73].

##### Measurement

Measurement of electrolytes is a commonly performed diagnostic procedure, performed via There was an error working with the wiki: Code[8], and is often impossible without parallel measurement of There was an error working with the wiki: Code[74]. Electrolytes measured most often are sodium and potassium. Chloride levels are rarely measured except for There was an error working with the wiki: Code[75] interpretation, as they are inherently linked to sodium levels. One important test conducted on urine is the There was an error working with the wiki: Code[76] test to determine the occurrence of electrolyte imbalance.

##### Nutritional significance

In There was an error working with the wiki: Code[77], electrolyte drinks containing sodium and potassium salts are used to replenish the body's Water and electrolyte levels after There was an error working with the wiki: Code[78] caused by There was an error working with the wiki: Code[79], There was an error working with the wiki: Code[80], There was an error working with the wiki: Code[81], There was an error working with the wiki: Code[82] or There was an error working with the wiki: Code[83]. Giving pure water to such a person is not the best way to restore fluid levels, because it dilutes the salts inside the body's cells and interferes with their chemical functions. This can lead to There was an error working with the wiki: Code[84].

There was an error working with the wiki: Code[85]s such as There was an error working with the wiki: Code[86] or There was an error working with the wiki: Code[87] are electrolyte drinks with large amounts of added There was an error working with the wiki: Code[88]s, such as There was an error working with the wiki: Code[89], to provide energy. The drinks commonly sold to the public are There was an error working with the wiki: Code[90] (with There was an error working with the wiki: Code[91] close to that of blood), with There was an error working with the wiki: Code[92] (with a lower osmolality) and There was an error working with the wiki: Code[93] (with a higher osmolality) varieties available to athletes, depending on their nutritional needs.http://www.disen.org/nutrition/pages-to-edit/fluids.htm

Because sports drinks contain very high levels of sugar, they are not recommended for regular use by children. Rather, specially-formulated pediatric electrolyte solutions are recommended. Sports drinks are also not appropriate for replacing the fluid lost during diarrhea. The role of sports drinks are to inhibit electrolyte loss, but are insufficient to restore imbalance once it occurs. Medicinal rehydration sachets and drinks are available to replace the key electrolyte ions lost. Dentists recommend that regular consumers of sports drinks observe precautions against There was an error working with the wiki: Code[94].

Electrolyte and sports drinks can be home-made by using the correct proportions of sugar, salt and water. http://www.webmd.com/hw/health_guide_atoz/str2254.asp?navbar=hw86827

#### Electrolytes in electrochemistry

When two There was an error working with the wiki: Code[95]s are placed in an electrolyte and a Voltage is applied, the electrolyte will conduct electricity. Lone Electrons normally cannot pass through the electrolyte instead, a chemical reaction occurs at the There was an error working with the wiki: Code[96] consuming electrons from the cathode, and another reaction occurs at the There was an error working with the wiki: Code[97] producing electrons to be taken up by the anode. As a result, a negative charge cloud develops in the electrolyte around the cathode, and a positive charge develops around the anode. The ions in the electrolyte move to neutralize these charges so that the reactions can continue and the electrons can keep flowing.

For example, in a dilute solution of ordinary salt (There was an error working with the wiki: Code[98], NaCl) in water, the cathode reaction will be

:2H2O + 2e&minus ? 2OH&minus + H2

and Hydrogen gas will bubble up the anode reaction is

:2H2O ? O2 + 4H+ + 4e&minus

and Oxygen gas will be liberated. The positively charged sodium ions Na+ will move towards the cathode neutralizing the negative charge of OH&minus there, and the negatively charged chlorine ions Cl&minus will move towards the anode neutralizing the positive charge of H+ there. Without the ions from the electrolyte, the charges around the electrode would slow down continued electron flow There was an error working with the wiki: Code[99] of H+ and OH&minus through water to the other electrode takes longer than movement of the much more prevalent salt ions.

In other systems, the electrode reactions can involve the metals of the electrodes as well as the ions of the electrolyte.

Electrolytic conductors are used in electronic devices where the chemical reaction at a metal/electrolyte interface yields useful effects.

In Battery (electricity), two There was an error working with the wiki: Code[100]s with different electron affinities are used as electrodes electrons flow from one electrode to the other outside of the battery, while inside the battery the circuit is closed by the electrolyte's ions. Here the electrode reactions slowly use up the chemical energy stored in the electrolyte.

In some Fuel cells, a solid electrolyte or There was an error working with the wiki: Code[101] connects the plates electrically while keeping the hydrogen and oxygen fuel gases separated.

In There was an error working with the wiki: Code[102] tanks, the electrolyte simultaneously deposits metal onto the object to be plated, and electrically connects that object in the circuit.

In operation-hours gauges, two thin columns of There was an error working with the wiki: Code[9] are separated by a small electrolyte-filled gap, and, as charge is passed through the device, the metal dissolves on one side and plates out on the other, causing the visible gap to slowly move along.

In There was an error working with the wiki: Code[10] coating, while the electrolyte layer behaves as one capacitor plate.

In some There was an error working with the wiki: Code[103]s the humidity of air is sensed by measuring the conductivity of a nearly dry electrolyte. Hot, softened glass is an electrolytic conductor, and some glass manufacturers keep the glass molten by passing a large electric current through it.

#### Electrolysis

In chemistry and manufacturing, electrolysis is a method of separating bonded There was an error working with the wiki: Code[11]s and There was an error working with the wiki: Code[12]s by passing an Electric current through them.

##### Overview

An Ionic compound is dissolved with an appropriate There was an error working with the wiki: Code[104], or otherwise melted by heat, so that its Ions are available in the liquid. An electrical current is applied between a pair of inert There was an error working with the wiki: Code[105]s immersed in the liquid. The negatively charged electrode is called the There was an error working with the wiki: Code[106], and the positively charged one the There was an error working with the wiki: Code[107].

Each electrode attracts ions which are of the opposite Electric charge. Therefore, positively charged ions (called There was an error working with the wiki: Code[108]s) move towards the cathode, while negatively charged ions (termed There was an error working with the wiki: Code[109]s) move toward the anode. The energy required to separate the ions, and cause them to gather at the respective electrodes, is provided by an electrical power supply. At the probes, Electrons are absorbed or released by the ions, forming a collection of the desired element or compound.

The amount of electrical energy that must be added equals the change in There was an error working with the wiki: Code[13] efficiency equals the There was an error working with the wiki: Code[110] change divided by the free energy change of the reaction. In most cases the electric input is larger than the enthalpy change of the reaction, so some energy is released in the form of heat. In some cases, for instance in the electrolysis of There was an error working with the wiki: Code[111] into hydrogen and oxygen at high temperature, the opposite is true. Heat is absorbed from the surroundings, and the There was an error working with the wiki: Code[112] of the produced hydrogen is higher than the electric input. In this case the efficiency can be said to be greater than 100%. (It is worth noting that the maximum theoretic efficiency of a Fuel cell is the inverse of that of electrolysis. It is thus impossible to create a Perpetual motion machine by combining the two processes. See Water fuel cell for an example of such an attempt.)

In electrolysis, the anode is the positive electrode, meaning it has a deficit of electrons species in contact with the anode can be stripped of electrons (i.e., they are oxidized). The cathode is the negative electrode, meaning it has a surplus of electrons. Species in contact with the cathode tend to gain electrons (i.e., they are reduced).

A higher current flow (amperage) through the cell means it will be passing more electrons through it at any given time. This means a faster rate of reduction at the cathode and a faster rate of oxidation at the anode. This corresponds to a greater number of moles of product. The amount of current that passes depends on the conductance of the electrodes and electrolyte, though it also depends on how much current the power source itself can generate.

Current also makes a difference in that it can shift chemical equilibria by sheer mass action. The processes in an electrolytic cell with just two or three reactants can become very, very complex. Most of the time it's best to search the literature to see what current density works best for a desired process. For instance, metals plated at a certain current density might form a durable and shiny coating on the substrate, while some other current density might form an excessively grainy, dull coating.

A higher potential difference (voltage) applied to the cell means the cathode will have more energy to bring about reduction, and the anode will have more energy to bring about oxidation. Higher potential difference enables the electrolytic cell to oxidize and reduce energetically more "difficult" compounds. This can drastically change what products will form in a given experiment. On a practical level, both current and voltage determine what will form in a cell.

The following technologies are related to electrolysis:

There was an error working with the wiki: Code[113]s, including the hydrogen Fuel cell, use the reverse of this process.

There was an error working with the wiki: Code[114] is an electrolysis where the solvent is a gel: it is used to separate substances, such as There was an error working with the wiki: Code[115] strands, based on their electrical charge.

##### Electrolysis of water

Electrolysis of water is an Electrolysis process which decomposes There was an error working with the wiki: Code[14] into There was an error working with the wiki: Code[15], where a power source from a 6 There was an error working with the wiki: Code[16] (usually an There was an error working with the wiki: Code[17] of a source of Direct current.

One important use of electrolysis is to produce hydrogen. The reaction that occurs is

:2H2O(aq) ? 2H2(g) + O2(g)

This has been suggested as a way of shifting society toward using hydrogen as an There was an error working with the wiki: Code[116] for powering electric motors and internal combustion engines. (See There was an error working with the wiki: Code[117].) Electrolysis of water can be achieved in a simple hands-on project, where electricity from a battery or low-voltage DC power supply (e.g. computer power supply 5 volt rail) is passed through a cup of water (in practice a saltwater solution or other electrolyte will need to be used otherwise no result will be observed). Using There was an error working with the wiki: Code[118] electrodes, hydrogen gas will be seen to bubble up at the cathode, and oxygen will bubble at the anode. If, however, any other metal is utilised for the anode the oxygen will react with the anode instead of being released as a gas. For example using iron electrodes in a sodium chloride solution electrolyte, iron oxide will be produced at the anode, which will react to form iron hydroxide. When producing large quantites of hydrogen, this can significantly contaminate the electrolytic cell - which is why iron is not used for commercial electrolysis.

The There was an error working with the wiki: Code[119] of water electrolysis varies widely. The efficiency is a measure of what fraction of electrical energy used is actually contained within the hydrogen. Some of the electrical energy is converted to heat, a useless by-product. Some reports quote efficiencies between 50–70%This efficiency is based on the Lower Heating Value of Hydrogen. The Lower Heating Value of Hydrogen is thermal energy released when Hydrogen is combusted. This does not represent the total amount of energy within the Hydrogen, hence the efficiency is lower than a more strict definition. Other reports quote the theoretical maximum efficiency of electrolysis. The theoretical maximum efficiency is between 80–94%.<pesn type=. The theoretical maximum considers the total amount of energy absorbed by both the hydrogen and oxygen. These values only refer to the efficiency of converting electrical energy into hydrogen's chemical energy. The energy lost in generating the electricity is not included. For instance, when considering a [[nuclear power plant|power plant"></pesn>] that converts the heat of nuclear reactions into hydrogen via electrolysis, the total efficiency is more like 25–40%.http://www.uic.com.au/nip73.htm

The electric current disassociates There was an error working with the wiki: Code[18] into There was an error working with the wiki: Code[120] (OH^{-})\, and Hydrogen H^{+}\, Ions.

In the electrolytic cell, at the There was an error working with the wiki: Code[19] reaction that forms hydrogen gas:

:\mbox{Cathode (reduction): }2H_{2}O(l) + 2e^{-} \rightarrow H_{2}(g) + 2OH^{-}(aq)\,

At the There was an error working with the wiki: Code[121], hydroxide ions undergo an There was an error working with the wiki: Code[122] reaction and give up There was an error working with the wiki: Code[123] to the anode to complete the circuit and form water and oxygen gas:

:\mbox{Anode (oxidation): }2H_{2}O(l) \rightarrow O_{2}(g) + 4H^{+}(aq) + 4e^{-}\,

hence decomposing water into Oxygen and Hydrogen

:\mbox{Overall reaction: }2H_{2}O(l) \rightarrow 2H_{2}(g) + O_{2}(g)\,

The volume of hydrogen gas produced is therefore twice the amount of oxygen gas. Assuming equal temperature and pressure for both gases, the hydrogen gas has twice the volume of the oxygen.

##### Spontaneity of the process

Decomposition of There was an error working with the wiki: Code[20] is not favorable in There was an error working with the wiki: Code[21] terms as half reactions standard potential are negative values,

:\mbox{Anode (oxidation): }2H_{2}O(l) \rightarrow O_{2}(g) + 4H^{+}(aq) + 4e^{-}\qquad E^{o}_{red}=-1.23 V\,

:\mbox{Cathode (reduction): }2H_{2}O(g) + 2e^{-} \rightarrow H_{2}(g) + 2OH^{-}(aq)\qquad E^{o}_{red}=-0.83 V\,

, on the other hand There was an error working with the wiki: Code[124] for the process at standard conditions is a higher positive value, about 474.4 kJ\,. Those considerations makes the process "impossible" to occur without adding electrolytes in the There was an error working with the wiki: Code[125].

##### Electrolyte selection

As Water conducts electricity very poorly, a water-soluble Electrolyte must be added to the electrolysis cell to close the circuit. The electrolyte dissolves and disassociates into There was an error working with the wiki: Code[126] and There was an error working with the wiki: Code[127] (positive and negative Ions) that carry the current. Electrolytes are normally There was an error working with the wiki: Code[128], There was an error working with the wiki: Code[129], or There was an error working with the wiki: Code[130].

Care must be taken in choosing an electrolyte, since an There was an error working with the wiki: Code[131] from the electrolyte is in competition with the hydroxide ions to give up an Electron. An electrolyte There was an error working with the wiki: Code[131] with less There was an error working with the wiki: Code[133] than hydroxide will be oxidized instead of the hydroxide, and no oxygen gas will be produced. A There was an error working with the wiki: Code[134] with a greater There was an error working with the wiki: Code[133] than a hydrogen ion will be reduced in its stead, and no hydrogen gas will be produced.

The following There was an error working with the wiki: Code[22]+, There was an error working with the wiki: Code[23]+, There was an error working with the wiki: Code[24]+, There was an error working with the wiki: Code[25]+, There was an error working with the wiki: Code[26]2+, There was an error working with the wiki: Code[27]2+, There was an error working with the wiki: Code[28]2+, There was an error working with the wiki: Code[29]+, and There was an error working with the wiki: Code[30]2+. There was an error working with the wiki: Code[136] and There was an error working with the wiki: Code[137] are frequently used, as they form inexpensive, soluble salts.

If an There was an error working with the wiki: Code[138] is used as the Electrolyte, the cation is H+, and there is no competitor for the H+ created by disassociating water.

The most commonly used There was an error working with the wiki: Code[139] is SO42-, as it is very difficult to oxidize.

Standard potential for oxidation of this ion to the peroxydisulfate ion is ?2.05 volts.

:\mbox{Anode (oxidation): } 2 SO^{2-}_{4} \rightarrow S_{2}O^{2-}_{8} + 2e^{-} \qquad E^{o}_{ox}=-2.05 V \,

Strong acids such as There was an error working with the wiki: Code[140] (H2SO4) are frequently used as electrolytes.

##### Examples

Electrolysis of an aqueous solution of table salt (NaCl, or There was an error working with the wiki: Code[141]) produces aqueous There was an error working with the wiki: Code[142] and There was an error working with the wiki: Code[143], although usually only in minute amounts. NaCl(aq) can be reliably electrolysed to produce hydrogen. In order to produce chlorine commercially, molten sodium chloride is electrolysed to produce sodium metal and chlorine gas. These will react violently, so a There was an error working with the wiki: Code[144] is used to ensure they do not come into contact with each other.

#### Techniques

A reaction is simple to replicate. Two leads running from the terminals of a battery into a cup of water and electrolyte are sufficient to produce a visible stream of oxygen or hydrogen bubbles at either There was an error working with the wiki: Code[145]. The presence of There was an error working with the wiki: Code[146] (OH-) Ions can be detected with a There was an error working with the wiki: Code[147] such as There was an error working with the wiki: Code[148] or There was an error working with the wiki: Code[149].

##### Hofmann voltameter

The There was an error working with the wiki: Code[150] is often used as a small-scale electrolytic cell. It consists of three joined upright cylinders. The inner cylinder is open at the top to allow the addition of Water and the Electrolyte. A There was an error working with the wiki: Code[151] electrode is placed at the bottom of each of the two side cylinders, connected to the positive and negative terminals of a source of Electricity. When current is run through the hofmann voltameter, gaseous Oxygen forms at the There was an error working with the wiki: Code[152] and gaseous Hydrogen at the There was an error working with the wiki: Code[153]. Each gas displaces water and collects at the top of the two outer tubes, where it can be drawn off with a stopcock.

##### Industrial electrolysis

Many industrial electrolysis cells are very similar to There was an error working with the wiki: Code[31], with complex platinum plates or honeycombs as electrodes. Hydrogen gas is usually created, collected, and burned on the premises, as its energy density per volume is too low to make transporting or storing it economically feasible. Oxygen gas is treated as a byproduct.

##### High-temperature electrolysis

High-temperature electrolysis (also HTE or steam electrolysis) is a method currently being investigated for the production of Hydrogen from water with Oxygen as a by-product. High-temperature electrolysis (also HTE or steam electrolysis) is a method currently being investigated for water electrolysis with a Heat engine. High temperature electrolysis is more efficient than traditional room-temperature electrolysis because some of the energy is supplied as heat, which is cheaper than electricity, and because the electrolysis reaction is more efficient at higher temperatures.

##### Efficiency

High temperature electrolysis is more efficient than traditional room-temperature Electrolysis of water because some of the energy is supplied as heat, which is cheaper than electricity, and because the electrolysis reaction is more efficient at higher temperatures. In fact, at 2500°C, electrical input is unnecessary because water breaks down to hydrogen and oxygen through There was an error working with the wiki: Code[154]. Such temperatures are impractical proposed HTE systems operate at 100 to 850°C.

The efficiency improvement of high-temperature electrolysis is best appreciated by assuming the electricity used comes from a Heat engine, and then considering the amount of heat energy necessary to produce one kg hydrogen (145 megajoules), both in the HTE process itself and also in producing the electricity used. At 100°C, 350 megajoules of thermal energy are required (41% efficient). At 850°C, 225 megajoules are required (64% efficient).

##### Economic potential

HTE does not provide a means to bypass the inherent inefficiency of a heat engine, by producing hydrogen which is then converted back to electricity in a fuel cell. (Any such efficiency improvement would allow the theoretical construction of a perpetual motion machine, which is impossible.) Thus any economic advantage to be gained from using HTE must come from supplying chemical processes which use hydrogen as a feedstock and not as a power source (such as the petrochemical or fertilizer industries), or motive processes for which hydrogen is a better energy carrier than electricity (rockets are an example, cars are not yet an example).

High-temperature electrolysis cannot compete with the chemical conversion of hydrocarbon or coal energy into hydrogen, as none of those conversions are limited by heat engine efficiency. Thus the possible supplies of cheap high-temperature heat for HTE are all nonchemical, including There was an error working with the wiki: Code[32], and There was an error working with the wiki: Code[155] sources.

#### Electrolysis and thermodynamics

During electrolysis, the amount of electrical energy that must be added equals the change in There was an error working with the wiki: Code[33] efficiency of any electrochemical process equals 100%. In practice, the efficiency is given by electrical work achieved divided by the Gibbs free energy change of the reaction.

In most cases, such as room temperature water electrolysis, the electric input is larger than the enthalpy change of the reaction, so some energy is released as waste heat. In some other cases however, for instance in the electrolysis of There was an error working with the wiki: Code[156] into hydrogen and oxygen at high temperature, the opposite is true. Heat is absorbed from the surroundings, and the There was an error working with the wiki: Code[157] of the produced hydrogen is higher than the electric input. In this case the efficiency relative to electric energy input can be said to be greater than 100%. It is worth noting that the maximum theoretic efficiency of a Fuel cell is the inverse of that of electrolysis. It is thus impossible to create a Perpetual motion machine by combining the two processes.

##### General energy efficiency

The There was an error working with the wiki: Code[158] of water electrolysis varies widely. Some report 50–70%while others report 80–94%.<pesn type= These values refer only to the efficiency of converting electrical energy into hydrogen's chemical energy. The energy lost in generating the electricity is not included. For instance, when considering a power plant that converts the heat of nuclear reactions into hydrogen via electrolysis, the total efficiency is more like 25–40%.[http://www.uic.com.au/nip73.htm"></pesn>

##### Laws of electrolysis

In There was an error working with the wiki: Code[34]. Faraday also discovered that the Mass of the resulting separated elements was directly proportional to the There was an error working with the wiki: Code[159]es of the elements when an appropriate integral divisor was applied. This provided strong evidence that discrete particles of electricity existed as parts of the atoms of elements.

##### Experimenters

Scientific pioneers of electrolysis included:

Humphry Davy

There was an error working with the wiki: Code[35]

There was an error working with the wiki: Code[160]

There was an error working with the wiki: Code[161]

More recently, electrolysis of There was an error working with the wiki: Code[36], resulting in anomalous heat generation and the controversial claim of Cold fusion.

#### Applications

About four percent of There was an error working with the wiki: Code[37].

##### The market for hydrogen production

Given a cheap, high-temperature heat source, other hydrogen production methods are possible. In particular, see the thermochemical There was an error working with the wiki: Code[162]. Thermochemical production might reach higher efficiencies than HTE because no heat engine is required. However, large-scale thermochemical production will require significant advances in materials that can withstand high-temperature, high-pressure, highly-corrosive environments.

The market for hydrogen is large (50 million metric tons/year in 2004, worth about \$135 billion/year) and growing at about 10% per year (see There was an error working with the wiki: Code[163]). The two major consumers are currently oil refineries and fertilizer plants (each consume about half of all production). Should hydrogen-powered cars become widespread, their consumption would greatly increase the demand for hydrogen.

##### Industrial uses

Manufacture of There was an error working with the wiki: Code[164], There was an error working with the wiki: Code[165], There was an error working with the wiki: Code[166], There was an error working with the wiki: Code[167], There was an error working with the wiki: Code[168].

Manufacture of Hydrogen for There was an error working with the wiki: Code[169]s and Fuel cells.

High-temperature electrolysis is also being used for this.

There was an error working with the wiki: Code[38] techniques can be used to determine the amount of matter transformed during electrolysis by measuring the amount of electricity required to perform the electrolysis.

Manufacture of There was an error working with the wiki: Code[170] and There was an error working with the wiki: Code[171].

Manufacture of sodium and potassium There was an error working with the wiki: Code[172].

Manufacture of perfluorinated organic compounds like There was an error working with the wiki: Code[173].

##### Military uses

As well as producing hydrogen, electrolysis also produces oxygen. There was an error working with the wiki: Code[39] or There was an error working with the wiki: Code[174]s.

#### Related concepts

There was an error working with the wiki: Code[175]

The There was an error working with the wiki: Code[176]

There was an error working with the wiki: Code[177]

There was an error working with the wiki: Code[178]

There was an error working with the wiki: Code[179]

There was an error working with the wiki: Code[180]

#### External articles and references

Fluids and Hydration in Sport - includes a discussion of the role of There was an error working with the wiki: Code[181], There was an error working with the wiki: Code[182] and There was an error working with the wiki: Code[183] drinks.

There was an error working with the wiki: Code[1], Wikipedia: The Free Encyclopedia. Wikimedia Foundation.

Electrolysis of Water, Experiments on Electrochemistry

Electrolysis of Water, Do Chem 044

U.S. DOE factsheet for high-temperature electrolysis