Illustration of a redox reaction

Redox (shorthand for reduction/oxidation reaction) describes all chemical reactions in which atoms have their oxidation number (oxidation state) changed. A chemical reaction is a process that always results in the interconversion of Chemical substances The substance or substances initially involved in a chemical reaction are called The oxidation number of a central atom in a coordination compound is the charge that it would have if all the Ligands were removed along with the Electron pairs In Chemistry, the oxidation state is an indicator of the degree of Oxidation of an Atom in a Chemical compound.

This can be either a simple redox process such as the oxidation of carbon to yield carbon dioxide, or the reduction of carbon by hydrogen to yield methane (CH4), or it can be a complex process such as the oxidation of sugar in the human body through a series of very complex electron transfer processes. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Methane is a Chemical compound with the molecular formula. It is the simplest Alkane, and the principal component of Natural gas. Sugar is a class of edible Crystalline substances mainly Sucrose, Lactose, and Fructose. Electron transfer (ET is the process by which an Electron moves from one Atom or Molecule to another atom or molecule

The term redox comes from the two concepts of reduction and oxidation. It can be explained in simple terms:

Though sufficient for many purposes, these descriptions are not precisely correct. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J In Chemistry, a molecule is defined as a sufficiently stable electrically neutral group of at least two Atoms in a definite arrangement held together by History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J In Chemistry, a molecule is defined as a sufficiently stable electrically neutral group of at least two Atoms in a definite arrangement held together by History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Oxidation and reduction properly refer to a change in oxidation number—the actual transfer of electrons may never occur. Thus, oxidation is better defined as an increase in oxidation number, and reduction as a decrease in oxidation number. In practice, the transfer of electrons will always cause a change in oxidation number, but there are many reactions which are classed as "redox" even though no electron transfer occurs (such as those involving covalent bonds).

Non-redox reactions, which do not involve changes in formal charge, are known as metathesis reactions. Chemistry, a formal charge (FC is a Partial charge on an Atom in a Molecule assigned by assuming that Electrons in a Chemical Metathesis is a bimolecular process involving the exchange of bonds between the two reacting Chemical species, which results in the creation of products with similar

The two parts of a redox reaction
Rusting iron
A bonfire. Combustion consists of redox reactions involving free radicals. In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell

## Oxidizing and reducing agents

Substances that have the ability to oxidize other substances are said to be oxidative and are known as oxidizing agents, oxidants or oxidizers. An oxidizing agent or oxidising agent (also called an oxidant, oxidizer or oxidiser) can be defined as either a Chemical compound Put another way, the oxidant removes electrons from another substance, and is thus reduced itself. And because it "accepts" electrons it is also called an electron acceptor. An electron acceptor is a chemical entity that accepts Electrons transferred to it from another compound

Oxidants are usually chemical substances with elements in high oxidation numbers (e. g. , H2O2, MnO4, CrO3, Cr2O72−, OsO4) or highly electronegative substances that can gain one or two extra electrons by oxidizing a substance (O, F, Cl, Br). Hydrogen peroxide (H2O2 is a very pale blue liquid which appears colorless in a dilute solution slightly more Viscous than water The acid Anhydride of Chromic acid, CrO3 is chromium trioxide or chromium(VI oxide; industrially this compound is sometimes sold as " Osmium tetroxide is the Chemical compound with the formula OsO4 " Electronegativity " is the opposite of " Electropositivity," which describes an element's ability to donate electrons Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Fluorine, fluorum meaning "to flow" is the Chemical element with the symbol F and Atomic number 9 Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and

Substances that have the ability to reduce other substances are said to be reductive and are known as reducing agents, reductants, or reducers. A reducing agent (also called a reductant or reducer) is the element or a compound in a Redox (reduction-oxidation reaction (see Electrochemistry Put in another way, the reductant transfers electrons to another substance, and is thus oxidized itself. And because it "donates" electrons it is also called an electron donor. An electron donor is a chemical entity that donates Electrons to another compound Reductants in chemistry are very diverse. Metal reduction—electropositive elemental metals can be used (Li, Na, Mg, Fe, Zn, Al). The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across These metals donate or give away electrons readily. Other kinds of reductants are hydride transfer reagents (NaBH4, LiAlH4), these reagents are widely used in organic chemistry[1][2], primarily in the reduction of carbonyl compounds to alcohols. Organic chemistry is a discipline within Chemistry which involves the scientific study of the structure properties composition reactions, and preparation In Organic chemistry, a carbonyl group is a Functional group composed of a Carbon Atom double-bonded to an Oxygen In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon Another useful method is reductions involving hydrogen gas (H2) with a palladium, platinum, or nickel catalyst. Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28 Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst These catalytic reductions are primarily used in the reduction of carbon-carbon double or triple bonds.

The chemical way to look at redox processes is that the reductant transfers electrons to the oxidant. Thus, in the reaction, the reductant or reducing agent loses electrons and is oxidized and the oxidant or oxidizing agent gains electrons and is reduced. The pair of an oxidizing and reducing agent that are involved in a particular reaction is called a redox pair.

## Examples of redox reactions

A good example is the reaction between hydrogen and fluorine:

$\mathrm{H}_{2} + \mathrm{F}_{2} \longrightarrow 2\mathrm {HF}$

We can write this overall reaction as two half-reactions: the oxidation reaction

$\mathrm{H}_{2} \longrightarrow 2\mathrm{H}^{+} + 2e^-$

and the reduction reaction:

$\mathrm{F}_{2} + 2e^- \longrightarrow 2\mathrm{F}^{-}$

Analysing each half-reaction in isolation can often make the overall chemical process clearer. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Fluorine, fluorum meaning "to flow" is the Chemical element with the symbol F and Atomic number 9 Because there is no net change in charge during a redox reaction, the number of electrons in excess in the oxidation reaction must equal the number consumed by the reduction reaction (as shown above).

Elements, even in molecular form, always have an oxidation number of zero. In the first half reaction, hydrogen is oxidized from an oxidation number of zero to an oxidation number of +1. In the second half reaction, fluorine is reduced from an oxidation number of zero to an oxidation number of −1.

When adding the reactions together the electrons cancel:

$\frac{\begin{array}{rcl}\mathrm{H}_{2} & \longrightarrow & 2\mathrm{H}^{+} + 2e^{-}\\\mathrm{F}_{2} + 2e^{-} & \longrightarrow & 2\mathrm{F}^{-}\end{array}}{\begin{array}{rcl}\mathrm{H}_{2} + \mathrm{F}_{2} & \longrightarrow & 2\mathrm{H}^{+} + 2\mathrm{F}^{-}\end{array}}$

And the ions combine to form hydrogen fluoride:

$\mathrm{H}_{2} + \mathrm{F}_{2}\, \ \longrightarrow \ 2\mathrm{H}^{+} + 2\mathrm{F}^{-}\ \longrightarrow \ 2\mathrm{HF}$

### Displacement reactions

Redox occurs in single displacement reactions or substitution reactions. Hydrofluoric acid is a Solution of Hydrogen fluoride in Water. A single-displacement reaction, also called single-replacement reaction, is when an element or ion moves out of one compound and into another In a substitution reaction, a Functional group in a particular Chemical compound is replaced by another group The redox component of this type of reaction is the change of oxidation state (charge) on certain atoms, not the actual exchange of atoms in the compounds.

For example, in the reaction between iron and copper(II) sulphate solution:

$\mathrm{Fe} + \mathrm{CuSO}_{4} \longrightarrow \mathrm{FeSO}_{4} + \mathrm{Cu}$

The ionic equation for this reaction is:

$\mathrm{Fe} + \mathrm{Cu}^{2+} \longrightarrow \mathrm{Fe}^{2+} + \mathrm{Cu}$

As two half-equations, it is seen that the iron is oxidized:

$\mathrm{Fe} \longrightarrow \mathrm{Fe}^{2+} + 2{e}^{-}$

And the copper is reduced:

$\mathrm{Cu}^{2+} + 2{e}^{-} \longrightarrow \mathrm{Cu}$

### Other examples

• iron(II) oxidizes to iron(III):
Fe2+ → Fe3+ + e
H2O2 + 2 e → 2 OH

overall equation for the above:

2Fe2+ + H2O2 + 2H+ → 2Fe3+ + 2H2O
2NO3 + 10e + 12 H+ → N2 + 6H2O
• iron oxidizes to iron(III) oxide and oxygen is reduced forming iron(III) oxide (commonly known as rusting, which is similar to tarnishing):
4Fe + 3O2 → 2 Fe2O3
• Combustion of hydrocarbons, e. Hydrogen peroxide (H2O2 is a very pale blue liquid which appears colorless in a dilute solution slightly more Viscous than water In Chemistry, hydroxide is the most common name for the diatomic Anion OH− consisting of Oxygen and Hydrogen Denitrification is a microbially facilitated process of dissimilatory nitrate reduction that may ultimately produce molecular Nitrogen (N2 through a series of intermediate In Inorganic chemistry, a nitrate is a salt of Nitric acid with an Ion composed of one Nitrogen and three Oxygen atoms Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 Rust is a general term for a series of Iron oxides, usually red oxides formed by the reaction of Iron with Oxygen in the presence of water or air Tarnish is a layer of Corrosion that develops over Copper, Brass, Silver, Aluminum as well as a degree of semi-reactive metals as Combustion or burning is a complex sequence of Exothermic chemical reactions between a Fuel and an Oxidant accompanied by the production of In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. g. in an internal combustion engine, produces water, carbon dioxide, some partially oxidized forms such as carbon monoxide and heat energy. The internal combustion engine is an engine in which the Combustion of Fuel and an Oxidizer (typically air occurs in a confined space called a Water is a common Chemical substance that is essential for the survival of all known forms of Life. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Carbon monoxide, with the chemical formula CO is a colorless odorless tasteless yet highly toxic Gas. In Physics and other Sciences energy (from the Greek grc ἐνέργεια - Energeia, "activity operation" from grc ἐνεργός Complete oxidation of materials containing carbon produces carbon dioxide. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6
• In organic chemistry, stepwise oxidation of a hydrocarbon produces water and, successively, an alcohol, an aldehyde or a ketone, carboxylic acid, and then a peroxide. Organic chemistry is a discipline within Chemistry which involves the scientific study of the structure properties composition reactions, and preparation In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon An aldehyde is an organic compound containing a terminal Carbonyl group. A ketone (pronounced as key tone) is either the Functional group characterized by a Carbonyl group (O=C linked to two other Carbon atoms or Carboxylic acids are Organic acids characterized by the presence of a Carboxyl group, which has the formula -C(=OOH usually written -COOH or -CO2H A peroxide is a compound containing an Oxygen -oxygen single bond.

## Redox reactions in industry

The primary process of reducing ore to produce metals is discussed in the article on Smelting. Chemical reduction, or smelting, is a form of Extractive metallurgy.

Oxidation is used in a wide variety of industries such as in the production of cleaning products.

Redox reactions are the foundation of electrochemical cells. An electrochemical cell is a device used for generating an Electromotive force ( Voltage) and current from chemical reactions.

## Redox reactions in biology

Many important biological processes involve redox reactions. This article deals with the molecular aspects of ascorbic acid A reducing agent (also called a reductant or reducer) is the element or a compound in a Redox (reduction-oxidation reaction (see Electrochemistry Vitamin C or L-ascorbate is an Essential nutrient for a large number of higher primate species a small number of other Mammalian Dehydroascorbic acid ( DHA) is an oxidized form of Ascorbic acid. An oxidizing agent or oxidising agent (also called an oxidant, oxidizer or oxidiser) can be defined as either a Chemical compound Vitamin C or L-ascorbate is an Essential nutrient for a large number of higher primate species a small number of other Mammalian Foundations of modern biology There are five unifying principles

Cellular respiration, for instance, is the oxidation of glucose (C6H12O6) to CO2 and the reduction of oxygen to water. Cellular respiration is the set of the metabolic reactions and processes that take place in Organisms cells to convert biochemical energy from Glucose (Glc a Monosaccharide (or simple Sugar) also known as grape sugar, is an important Carbohydrate in Biology. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Water is a common Chemical substance that is essential for the survival of all known forms of Life. The summary equation for cell respiration is:

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
The process of cell respiration also depends heavily on the reduction of NAD+ to NADH and the reverse reaction (the oxidation of NADH to NAD+). Photosynthesis is essentially the reverse of the redox reaction in cell respiration:
6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2

Biological energy is frequently stored and released by means of redox reactions. Photosynthesis is a Metabolic pathway that converts Light Energy into Chemical energy. In Physics, the photon is the Elementary particle responsible for electromagnetic phenomena Photosynthesis involves the reduction of carbon dioxide into sugars and the oxidation of water into molecular oxygen. Photosynthesis is a Metabolic pathway that converts Light Energy into Chemical energy. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single Sugar is a class of edible Crystalline substances mainly Sucrose, Lactose, and Fructose. Water ( H2[[oxygen O]] H OH) is the most abundant Molecule on Earth 's surface composing of about 70% of the Earth's surface as Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the The reverse reaction, respiration, oxidizes sugars to produce carbon dioxide and water. Cellular respiration is the set of the metabolic reactions and processes that take place in Organisms cells to convert biochemical energy from As intermediate steps, the reduced carbon compounds are used to reduce nicotinamide adenine dinucleotide (NAD+), which then contributes to the creation of a proton gradient, which drives the synthesis of adenosine triphosphate (ATP) and is maintained by the reduction of oxygen. Nicotinamide adenine dinucleotide, abbreviated NAD+, is a Coenzyme found in all living cells The compound is a dinucleotide since it consists In Cellular biology, an electrochemical gradient is a spatial variation of both Electrical potential and chemical Concentration across a membrane Adenosine-5'-triphosphate ( ATP) is a multifunctional Nucleotide that is most important as a " molecular currency" of intracellular Energy In animal cells, mitochondria perform similar functions. In Cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed Organelle found in most eukaryotic cells. See Membrane potential article. Membrane potential (or transmembrane potential) is the Voltage difference (or Electrical potential difference between the interior and exterior of a

The term redox state is often used to describe the balance of NAD+/NADH and NADP+/NADPH in a biological system such as a cell or organ. Nicotinamide adenine dinucleotide, abbreviated NAD+, is a Coenzyme found in all living cells The compound is a dinucleotide since it consists Nicotinamide adenine dinucleotide phosphate ( NADP+, in older notation triphosphopyridine nucleotide TPN) is used in anabolic reactions such as Lipid The redox state is reflected in the balance of several sets of metabolites (e. g. , lactate and pyruvate, beta-hydroxybutyrate and acetoacetate) whose interconversion is dependent on these ratios. Lactic acid ( IUPAC Systematic name: 2-hydroxypropanoic acid) also known as milk acid, is a Chemical compound that plays a role Pyruvic acid (CH3COCO2H is an alpha-keto acid. The Carboxylate Anion of pyruvic acid is known as pyruvate. beta -Hydroxybutyric acid ( beta -hydroxybutyrate or 3-hydroxybutyric acid is a Ketone body. Acetoacetic acid is the Organic compound with the formula CH3C(OCH2CO2H An abnormal redox state can develop in a variety of deleterious situations, such as hypoxia, shock, and sepsis. Chronic Hypoxia is a pathological condition in which the body as a whole ( generalized hypoxia) or region of the body ( tissue hypoxia) is deprived of adequate Sepsis is a serious medical condition characterized by a whole-body inflammatory state (called a Systemic inflammatory response syndrome or SIRS caused Redox signaling involves the control of cellular processes by redox processes. Redox signaling is the process wherein Free radicals, Reactive oxygen species (ROS and other electronically-activated species act as messengers in biological systems

### Redox cycling

A wide variety of aromatic compounds are enzymatically reduced to form free radicals that contain one more electron than their parent compounds. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell In general, the electron donor is any of a wide variety of flavoenzymes and their coenzymes. Coenzymes are small organic non- Protein Molecules that carry chemical groups between Enzymes Coenzymes are sometimes referred to as cosubstrates Once formed, these anion free radicals reduce molecular oxygen to superoxide and regenerate the unchanged parent compound. Superoxide is the Anion O2&minus It is important as the product of the one-electron reduction of Dioxygen, which occurs widely in nature The net reaction is the oxidation of the flavoenzyme's coenzymes and the reduction of molecular oxygen to form superoxide. This catalytic behavior has been described as futile cycle or redox cycling.

Examples of redox cycling-inducing molecules are the herbicide paraquat and other viologens and quinones such as menadione. A herbicide is used to kill unwanted Plants Selective herbicides kill specific targets while leaving the desired Crop relatively unharmed Paraquat is the trade name for NN'-Dimethyl-44'-bipyridinium dichloride, a Viologen. The Viologens are diquaternary derivatives of 44'-bipyridyl The name comes from the fact that this class of compounds is easily reduced to the radical mono "DDQ" redirects here DDQ is also the former callsign of a TV station in Toowoomba Queensland Australia Menadione is a Polycyclic Aromatic Ketone, based on 14-naphthoquinone, with a 2- Methyl Substituent. [1]PDF (2. 76 MiB)

## Balancing redox reactions

Describing the overall electrochemical reaction for a redox process requires a balancing of the component half reactions for oxidation and reduction. A mebibyte (a contraction of me ga bi nary byte) is a unit of Information or Computer storage, abbreviated MiB. A half reaction is either the oxidation or reduction reaction component of a Redox reaction. For reactions in aqueous solution, this general involves adding H+ , OH- ion, H2O and electrons to compensate the oxidation changes. The proton ( Greek πρῶτον / proton "first" is a Subatomic particle with an Electric charge of one positive In Chemistry, hydroxide is the most common name for the diatomic Anion OH− consisting of Oxygen and Hydrogen Water ( H2[[oxygen O]] H OH) is the most abundant Molecule on Earth 's surface composing of about 70% of the Earth's surface as

### Acid medium

In acid medium H+ ions and water are added to half reactions to balance the overall reaction. The proton ( Greek πρῶτον / proton "first" is a Subatomic particle with an Electric charge of one positive For example, when manganese (II) reacts with sodium bismuthate. Manganese (ˈmæŋgəniːz is a Chemical element, designated by the symbol Mn.

$\mbox{Reaction unbalanced: }\mbox{Mn}^{2+}(aq) + \mbox{NaBiO}_3(s)\rightarrow\mbox{Bi}^{3+}(aq) + \mbox{MnO}_4^{-}(aq)\,$
$\mbox{Oxidation: }\mbox{4H}_2\mbox{O}(l)+\mbox{Mn}^{2+}(aq)\rightarrow\mbox{MnO}_4^{-}(aq) + \mbox{8H}^{+}(aq)+\mbox{5e}^{-}\,$
$\mbox{Reduction: }\mbox{2e}^{-}+ \mbox{6H}^{+}(aq) + \mbox{BiO}_3^{-}(s)\rightarrow\mbox{Bi}^{3+}(aq) + \mbox{3H}_2\mbox{O}(l)\,$

The reaction is balanced by scaling the two half-cell reactions to involve the same number of electrons (i. e. multiplying the oxidation reaction by the number of electrons in the reduction step and vice versa). Addition gives:

$\mbox{8H}_2\mbox{O}(l)+\mbox{2Mn}^{2+}(aq)\rightarrow\mbox{2MnO}_4^{-}(aq) + \mbox{16H}^{+}(aq)+\mbox{10e}^{-}\,$
$\mbox{10e}^{-}+ \mbox{30H}^{+}(aq) + \mbox{5BiO}_3^{-}(s)\rightarrow\mbox{5Bi}^{3+}(aq) + \mbox{15H}_2\mbox{O}(l)\,$

Reaction balanced:

$\mbox{14H}^{+}(aq) + \mbox{2Mn}^{2+}(aq)+ \mbox{5NaBiO}_3(s)\rightarrow\mbox{7H}_2\mbox{O}(l) + \mbox{2MnO}_4^{-}(aq)+\mbox{5Bi}^{3+}(aq)+\mbox{5Na}^{+}(aq)\,$

Similarly for a propane fuel cell under acidic conditions:

$\mbox{Reaction unbalanced: }\mbox{C}_{3}\mbox{H}_{8}+\mbox{O}_{2}\rightarrow\mbox{CO}_{2}+\mbox{H}_{2}\mbox{O}\,$
$\mbox{Reduction: }\mbox{4H}^{+} + \mbox{O}_{2}+ \mbox{4e}^{-}\rightarrow\mbox{2H}_{2}\mbox{O}\,$
$\mbox{Oxidation: }\mbox{6H}_{2}\mbox{O}+\mbox{C}_{3}\mbox{H}_{8}\rightarrow\mbox{3CO}_{2}+\mbox{20e}^{-}+\mbox{20H}^{+}\,$

Balancing the number of electrons involved gives:

$\mbox{20H}^{+}+\mbox{5O}_{2}+\mbox{20e}^{-}\rightarrow\mbox{10H}_{2}\mbox{O}\,$
$\mbox{6H}_{2}\mbox{O}+\mbox{C}_{3}\mbox{H}_{8}\rightarrow\mbox{3CO}_{2}+\mbox{20e}^{-}+\mbox{20H}^{+}\,$

Equation balanced:

$\mbox{C}_{3}\mbox{H}_{8}+\mbox{5O}_{2}\rightarrow\mbox{3CO}_{2}+\mbox{4H}_{2}\mbox{O}\,$

### Basic medium

In basic medium OH- ions and water are added to half reactions to balance the overall reaction. Propane is a three- Carbon Alkane, normally a gas but compressible to a liquid that is transportable A fuel cell is an electrochemical conversion device It produces electricity from Fuel (on the Anode side and an oxidant (on the In Chemistry, hydroxide is the most common name for the diatomic Anion OH− consisting of Oxygen and Hydrogen Water ( H2[[oxygen O]] H OH) is the most abundant Molecule on Earth 's surface composing of about 70% of the Earth's surface as For example, in the reaction between potassium permanganate and sodium sulfite:

$\mbox{Reaction unbalanced: }\mbox{KMnO}_{4}+\mbox{Na}_{2}\mbox{SO}_3+\mbox{H}_2\mbox{O}\rightarrow\mbox{MnO}_{2}+\mbox{Na}_{2}\mbox{SO}_{4}+\mbox{KOH}\,$
$\mbox{Reduction: }\mbox{3e}^{-}+\mbox{2H}_{2}\mbox{O}+\mbox{MnO}_{4}^{-}\rightarrow\mbox{MnO}_{2}+\mbox{4OH}^{-}\,$
$\mbox{Oxidation: }\mbox{2OH}^{-}+\mbox{SO}^{2-}_{3}\rightarrow\mbox{SO}^{2-}_{4}+\mbox{H}_{2}\mbox{O}+\mbox{2e}^{-}\,$

Balancing the number of electrons in the two half-cell reactions gives:

$\mbox{6e}^{-}+\mbox{4H}_{2}\mbox{O}+\mbox{2MnO}_{4}^{-}\rightarrow\mbox{2MnO}_{2}+\mbox{8OH}^{-}\,$
$\mbox{6OH}^{-}+\mbox{3SO}^{2-}_{3}\rightarrow\mbox{3SO}^{2-}_{4}+\mbox{3H}_{2}\mbox{O}+\mbox{6e}^{-}\,$

Equation balanced:

$\mbox{2KMnO}_{4}+\mbox{3Na}_{2}\mbox{SO}_3+\mbox{H}_2\mbox{O}\rightarrow\mbox{2MnO}_{2}+\mbox{3Na}_{2}\mbox{SO}_{4}+\mbox{2KOH}\,$