17 sulfur ← chlorine → argon F ↑ Cl ↓ Br Periodic table - Extended periodic table
General
Name, symbol, number	chlorine, Cl, 17
Chemical series	nonmetals
Group, period, block	17, 3, p
Appearance	yellowish green
Standard atomic weight	35.453(2) g·mol−1
Electron configuration	[Ne] 3s2 3p5
Electrons per shell	2, 8, 7
Physical properties
Phase	gas
Density	(0 °C, 101. Sulfur or sulphur (ˈsʌlfɚ see spelling below) is the Chemical element that has the Atomic number 16 This article pertains to the chemical element For other uses see Argon (disambiguation. Fluorine, fluorum meaning "to flow" is the Chemical element with the symbol F and Atomic number 9 This is a typical display of the periodic table of the elements and contains the symbol and Atomic number of each element Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of Chemical elements, sorted by name Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of chemical elements by symbol, including the A table of Chemical elements ordered by Atomic number and color coded according to type of element In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in Nonmetal is a term used in Chemistry when classifying the Chemical elements On the basis of their general physical and chemical properties every element in the In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in In the Periodic table of the elements, a period is a horizontal row of the table A block of the Periodic table of elements is a set of adjacent groups The respective highest-energy electrons in each element in a block belong to the same Atomic Abundance Owing to their high Reactivity, the halogens are found in the environment only in compounds or as Ions Halide ions and oxoanions A period 3 element is one of the Chemical elements in the third row (or period) of the periodic table of the elements. See also Electron configuration The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass To help compare different orders of magnitude, the following list describes various Mass levels between 10&minus36&thinsp kg and 1053&thinspkg Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) In Atomic physics and Quantum chemistry, electron configuration is the arrangement of Electrons in an Atom, Molecule, or other Neon (ˈniːɒn is the Chemical element that has the symbol Ne and Atomic number 10 The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J An electron shell may be crudely thought of as an Orbit followed by Electrons around an Atom nucleus. In the Physical sciences a phase is a Set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties This page is about the physical properties of gas as a state of matter The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 325 kPa) 3. 2 g/L
Melting point	171. The melting point of a solid is the temperature range at which it changes state from solid to Liquid. 6 K (-101. The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic 5 °C, -150. The Celsius Temperature scale was previously known as the centigrade scale. 7 °F)
Boiling point	239. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 The boiling point of a liquid is the temperature at which the Vapor pressure of the liquid equals the environmental pressure surrounding the liquid 11 K (-34. The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic 4 °C, -29. The Celsius Temperature scale was previously known as the centigrade scale. 27 °F)
Critical point	416. Fahrenheit is a temperature scale named after Daniel Gabriel Fahrenheit (1686–1736 a German Physicist who proposed it in 1724 In Physical chemistry, Thermodynamics, Chemistry and Condensed matter physics, a critical point, also called a critical state 9 K, 7. The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic 991 MPa
Heat of fusion	(Cl2) 6. The standard Enthalpy of fusion (symbol \Delta{}H_{fus} also known as the heat of fusion or specific melting heat, is the amount of 406 kJ·mol−1
Heat of vaporization	(Cl2) 20. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material The enthalpy of vaporization, (symbol \Delta{}_{v}H also known as the heat of vaporization or heat of evaporation, is the Energy required 41 kJ·mol−1
Specific heat capacity	(25 °C) (Cl2) 33. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material Specific heat capacity, also known simply as specific heat, is the measure of the heat energy required to increase the Temperature of a unit quantity 949 J·mol−1·K−1
Vapor pressure P/Pa 1 10 100 1 k 10 k 100 k at T/K 128 139 153 170 197 239
Atomic properties
Crystal structure	orthorhombic
Oxidation states	±1, 3, 5, 7 (strongly acidic oxide)
Electronegativity	3. Vapor pressure (also known as equilibrium vapor pressure or saturation vapor pressure) is the Pressure of a Vapor in equilibrium In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. 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 Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are " Electronegativity " is the opposite of " Electropositivity," which describes an element's ability to donate electrons 16 (Pauling scale)
Ionization energies (more)	1st: 1251. The ionization potential, ionization energy or EI of an Atom or Molecule is the Energy required to remove an Electron These tables list the Ionization energy in kJ/mol necessary to remove one mole of Electrons from one mole of neutral gaseous Atoms (first energy respectively 2 kJ·mol−1
	2nd: 2298 kJ·mol−1
	3rd: 3822 kJ·mol−1
Atomic radius	100 pm
Atomic radius (calc. The joule per mole (symbol J·mol-1 is an SI derived unit of energy per amount of material Atomic radius, and more generally the size of an atom, is not a precisely defined Physical quantity, nor is it constant in all circumstances A picometre ( American spelling: picometer, symbol pm) is a unit of Length in the Metric system, equal to one trillionth )	79 pm
Covalent radius	99 pm
Van der Waals radius	175 pm
Miscellaneous
Magnetic ordering	nonmagnetic
Electrical resistivity	(20 °C) > 10 Ω·m
Thermal conductivity	(300 K) 8. The covalent radius, r cov is a measure of the size of Atom which forms part of a Covalent bond. Van der Waals Volume The van der Waals volume, V, also called the atomic volume or molecular volume, is the atomic property most directly In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. Electrical resistivity (also known as specific electrical resistance) is a measure of how strongly a material opposes the flow of Electric current. In Physics, thermal conductivity, k is the property of a material that indicates its ability to conduct Heat. 9x10-3  W·m−1·K−1
Speed of sound	(gas, 0 °C) 206 m/s
CAS registry number	7782-50-5
Selected isotopes
Main article: Isotopes of chlorine iso NA half-life DM DE (MeV) DP 35Cl 75. Sound is a vibration that travels through an elastic medium as a Wave. CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to Chlorine ( Cl) has isotopes with mass numbers ranging from 32 g mol−1 to 40 g mol−1 Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides In Chemistry, natural abundance (NA refers to the abundance Isotopes of a Chemical element as naturally found on a planet Half-Life (computer-game page here It's already listed in the disambiguation page Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. The decay energy is the Energy released by a Nuclear decay. The energy difference of the Reactants is often written as Q: where Q In Nuclear physics, a decay product, also known as a daughter product, daughter isotope or daughter nuclide, is a Nuclide 77% 35Cl is stable with 18 neutrons 36Cl syn 3.01×105 y β- 0. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. A synthetic radioisotope is a Radionuclide that is not found in nature no natural process or mechanism exists which produces it or it is so unstable that it decays away in To help compare Orders of magnitude of different times this page lists times between 32 000 Years and 320 000 years (1012 Seconds mdasha terasecond A year (from Old English gēr) is the time between two recurrences of an event related to the Orbit of the Earth around the Sun In Nuclear physics, beta decay is a type of Radioactive decay in which a Beta particle (an Electron or a Positron) is emitted 709 36Ar ε - 36S 37Cl 24. This article pertains to the chemical element For other uses see Argon (disambiguation. Electron capture (sometimes called inverse beta decay) is a Decay mode for Isotopes that will occur when there are too many Protons in the Sulfur or sulphur (ˈsʌlfɚ see spelling below) is the Chemical element that has the Atomic number 16 23% 37Cl is stable with 20 neutrons
References
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Chlorine (IPA: /ˈklɔəriːn/, from the Greek word 'χλωρóς' (khlôros) meaning 'green'), is the chemical element with atomic number 17 and symbol Cl. Stable isotopes are chemical isotopes that are not Radioactive (to current knowledge This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. Recommended values for many properties of the elements together with various references are collected on these data pages Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly A chemical element is a type of Atom that is distinguished by its Atomic number; that is by the number of Protons in its nucleus. See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton It is a halogen, found in the periodic table in group VII (formerly VIIa or VIIb). Abundance Owing to their high Reactivity, the halogens are found in the environment only in compounds or as Ions Halide ions and oxoanions The periodic table of the chemical elements is a tabular method of displaying the Chemical elements Although precursors to this table exist its invention is In Chemistry a group, also known as a family, is a vertical column in the Periodic table of the Chemical elements There are 18 groups in As the chloride ion, which is part of common salt and other compounds, it is abundant in nature and necessary to most forms of life, including humans. The chloride Ion is formed when the element Chlorine picks up one Electron to form an Anion (negatively-charged ion Cl&minus For sodium chloride in the diet see Salt. Sodium chloride, also known as common salt, table salt, or Halite, is a Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus In its common elemental form (Cl₂ or "dichlorine") under standard conditions, it is a pale green gas about 2. In Physical sciences standard conditions for temperature and pressure are Standard sets of conditions for experimental measurements to allow comparisons to be made 5 times as dense as air. It has a disagreeable, suffocating odor that is detectable in concentrations as low as 3. 5 ppm^[1] and is poisonous. In the context of Biology, poisons are substances that can cause damage, Illness, or Death to Organisms usually by Chlorine is a powerful oxidant and is used in bleaching and disinfectants. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state A bleach is a Chemical that removes color or whitens often via Oxidation. As a common disinfectant, chlorine compounds are used in swimming pools to keep them clean and sanitary. A swimming pool, swimming bath, wading pool, or simply a pool, is an artificially enclosed Body of water intended for Swimming or In the upper atmosphere, chlorine-containing molecules have been implicated in the destruction of the ozone layer. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Ozone depletion describes two distinct but related observations a slow steady decline of about 4 percent per decade in the total amount of Ozone in Earth's The photochemical mechanisms that give rise to the ozone layer were worked out by the British physicist Sidney Chapman in 1930

Contents 1 Characteristics 1.1 Isotopes 1.2 Occurrence 2 Production 2.1 Gas extraction 2.2 Other methods 2.3 Industrial production 3 Compounds 3.1 Oxidation states 4 Applications and uses 4.1 Production of industrial and consumer products 4.2 Purification and disinfection 4.3 Chemistry 4.4 Use as a weapon 4.5 Other uses 5 History 6 Safety 7 Chlorine cracking 8 See also 9 References 10 External links

Characteristics

Chlorine gas is diatomic, with the formula Cl₂. Diatomic molecules are molecules made only of two Atoms of either the same or different Chemical elements The prefix di- means two in Greek It combines readily with all elements except O₂ and N₂^[2] and the noble gases. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 History Noble gas is translated from the German noun de ''Edelgas'' first used in 1898 by Hugo Erdmann to indicate their extremely low level of reactivity Compounds with oxygen, nitrogen, and xenon are known but do not form by direct reaction of the elements. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 Xenon (ˈzɛnɒn or) is a Chemical element represented by the symbol Xe. ^[3] Chlorine, though very reactive, is not as extremely reactive as fluorine. Fluorine, fluorum meaning "to flow" is the Chemical element with the symbol F and Atomic number 9 Pure chlorine gas does, however, support combustion of organic compounds such as hydrocarbons, although the carbon component tends to burn incompletely, with much of it remaining as soot. In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. ^[4] At 10 °C and atmospheric pressure, one liter of water dissolves 3. The Celsius Temperature scale was previously known as the centigrade scale. The litre or liter (see spelling differences) is a unit of Volume. Water is a common Chemical substance that is essential for the survival of all known forms of Life. 10 L of gaseous chlorine, and at 30°C, 1 L of water dissolves only 1. 77 liters of chlorine. ^[2]

This element is a member of the salt-forming halogen series and is extracted from chlorides through oxidation often by electrolysis. Salt is a Dietary mineral composed primarily of Sodium chloride that is essential for Animal life but toxic to most land plants Abundance Owing to their high Reactivity, the halogens are found in the environment only in compounds or as Ions Halide ions and oxoanions Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current As the chloride ion, Cl⁻, it is also the most abundant dissolved ion in ocean water. An ocean (from Greek, ''Okeanos'' (Oceanus) is a major body of saline water, and a principal component of the Hydrosphere.

Isotopes

Main article: Isotopes of chlorine

Chlorine has isotopes with mass numbers ranging from 32 to 40. Chlorine ( Cl) has isotopes with mass numbers ranging from 32 g mol−1 to 40 g mol−1 The mass number ( A) also called atomic mass number or nucleon number, is the total number of Protons and Neutrons (together known as There are two principal stable isotopes, ³⁵Cl (75. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides 77%) and ³⁷Cl (24. 23%), giving chlorine atoms in bulk an apparent atomic weight of 35. History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny 4527 g/mol.

Trace amounts of radioactive ³⁶Cl exist in the environment, in a ratio of about 7x10⁻¹³ to 1 with stable isotopes. Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. Chlorine-36 is an Isotope of Chlorine. Chlorine has two Stable isotopes and one Radioactive environmental isotope: the cosmogenic isotope ³⁶Cl is produced in the atmosphere by spallation of ³⁶Ar by interactions with cosmic ray protons. In general spallation is a process in which fragments of material ( Spall) are ejected from a body due to impact or stress This article pertains to the chemical element For other uses see Argon (disambiguation. For the 1962 Bruce Conner film see Cosmic Ray (film Cosmic rays are energetic particles originating from space that impinge on The proton ( Greek πρῶτον / proton "first" is a Subatomic particle with an Electric charge of one positive In the subsurface environment, ³⁶Cl is generated primarily as a result of neutron capture by ³⁵Cl or muon capture by ⁴⁰Ca. Neutron capture is a kind of Nuclear reaction in which an Atomic nucleus collides with one or more Neutrons and they merge to form a heavier nucleus Muon capture is the capture of a negative Muon by a Proton, usually resulting in production of a Neutron and a Neutrino, and sometimes a Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 ³⁶Cl decays to ³⁶S and to ³⁶Ar, with a combined half-life of 308,000 years. Sulfur or sulphur (ˈsʌlfɚ see spelling below) is the Chemical element that has the Atomic number 16 This article pertains to the chemical element For other uses see Argon (disambiguation. Half-Life (computer-game page here It's already listed in the disambiguation page The half-life of this hydrophilic nonreactive isotope makes it suitable for geologic dating in the range of 60,000 to 1 million years. Hydrophile, from the Greek (hydros "water" and φιλια (philia "friendship" refers to a physical property of a Molecule Radiometric dating (often called radioactive dating) is a technique used to date materials usually based on a comparison between the observed abundance of a naturally occurring Additionally, large amounts of ³⁶Cl were produced by irradiation of seawater during atmospheric detonations of nuclear weapons between 1952 and 1958. Seawater is Water from a Sea or Ocean. On average seawater in the world's oceans has a Salinity of about 3 A nuclear weapon is an explosive device that derives its destructive force from Nuclear reactions either fission or a combination of fission and fusion. The residence time of ³⁶Cl in the atmosphere is about 1 week. Thus, as an event marker of 1950s water in soil and ground water, ³⁶Cl is also useful for dating waters less than 50 years before the present. Soil, often typeset as SOiL, is a four piece rock band from Chicago Illinois United States founded by Shaun Glass Tom Schofield Tim King and Adam Zadel Groundwater is Water located beneath the Ground surface in Soil pore spaces and in the Fractures of lithologic formations ³⁶Cl has seen use in other areas of the geological sciences, including dating ice and sediments.

Occurrence

See also Halide minerals.

In nature, chlorine is found primarily as the chloride ion, a component of the salt that is deposited in the earth or dissolved in the oceans — about 1. The chloride Ion is formed when the element Chlorine picks up one Electron to form an Anion (negatively-charged ion Cl&minus Salt is a Dietary mineral composed primarily of Sodium chloride that is essential for Animal life but toxic to most land plants An ocean (from Greek, ''Okeanos'' (Oceanus) is a major body of saline water, and a principal component of the Hydrosphere. 9% of the mass of seawater is chloride ions. Even higher concentrations of chloride are found in the Dead Sea and in underground brine deposits. The Dead Sea (יָם הַ‏‏מֶ‏ּ‏לַ‏ח, "Sea of Salt"البَحْر المَيّت, "Dead Sea" is a salt lake between Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl Most chloride salts are soluble in water, thus, chloride-containing minerals are usually only found in abundance in dry climates or deep underground. Common chloride minerals include halite (sodium chloride), sylvite (potassium chloride), and carnallite (potassium magnesium chloride hexahydrate). Halite is the Mineral form of Sodium chloride, Na[[chlorine Cl]] commonly known as rock salt. For sodium chloride in the diet see Salt. Sodium chloride, also known as common salt, table salt, or Halite, is a Sylvite is Potassium chloride ( K[[chlorine Cl]] in natural Mineral form The Chemical compound potassium chloride (KCl is a Metal Halide salt composed of Potassium and Chlorine. Carnallite is an Evaporite mineral a hydrated Potassium Magnesium Chloride with formula K[[magnesium Mg]] Cl 3·6( Over 2000 naturally-occurring organic chlorine compounds are known. ^[5]

Industrially, elemental chlorine is usually produced by the electrolysis of sodium chloride dissolved in water. In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current Along with chlorine, this chloralkali process yields hydrogen gas and sodium hydroxide, according to the following chemical equation:

2 NaCl + 2 H₂O → Cl₂ + H₂ + 2 NaOH

Production

Gas extraction

Chlorine can be manufactured by electrolysis of a sodium chloride solution (brine). A chloralkali process always implies the Electrolysis of common salt or Sodium chloride. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature A chemical equation is a symbolic representation of a Chemical reaction. For sodium chloride in the diet see Salt. Sodium chloride, also known as common salt, table salt, or Halite, is a Water is a common Chemical substance that is essential for the survival of all known forms of Life. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current For sodium chloride in the diet see Salt. Sodium chloride, also known as common salt, table salt, or Halite, is a In Chemistry, a solution is a Homogeneous Mixture composed of two or more substances Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl The production of chlorine results in the co-products caustic soda (sodium hydroxide, NaOH) and hydrogen gas (H₂). Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 These two products, as well as chlorine itself, are highly reactive. Chlorine can also be produced by the electrolysis of a solution of potassium chloride, in which case the co-products are hydrogen and caustic potash (potassium hydroxide). In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current In Chemistry, a solution is a Homogeneous Mixture composed of two or more substances The Chemical compound potassium chloride (KCl is a Metal Halide salt composed of Potassium and Chlorine. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Potassium hydroxide is the Inorganic compound with the formula K[[hydroxide OH]] Potassium hydroxide is the Inorganic compound with the formula K[[hydroxide OH]] There are three industrial methods for the extraction of chlorine by electrolysis of chloride solutions, all proceeding according to the following equations:

Cathode: 2 H⁺ (aq) + 2 e⁻ → H₂ (g)

Anode: 2 Cl⁻ (aq) → Cl₂ (g) + 2 e⁻

Overall process: 2 NaCl (or KCl) + 2 H₂O → Cl₂ + H₂ + 2 NaOH (or KOH)

• Mercury cell electrolysis

Mercury cell electrolysis, also known as the Castner-Kellner process, was the first method used at the end of the nineteenth century to produce chlorine on an industrial scale. In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current The Castner-Kellner process is a method of Electrolysis on an Aqueous Alkali Chloride solution (usually Sodium chloride solution ^[6][7] The "rocking" cells used have been improved over the years. ^[8] Today, in the "primary cell", titanium anodes (formerly graphite ones) are placed in a sodium (or potassium) chloride solution flowing over a liquid mercury cathode. Titanium (taɪˈteɪniəm is a Chemical element with the symbol Ti and Atomic number 22 The Mineral graphite, as with Diamond and Fullerene, is one of the Allotropes of carbon. Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum A cathode is an Electrode through which (positive Electric current flows out of a polarized electrical device When a potential difference is applied and current flows, chlorine is released at the titanium anode and sodium (or potassium) dissolves in the mercury cathode forming an amalgam. Titanium (taɪˈteɪniəm is a Chemical element with the symbol Ti and Atomic number 22 An anode is an Electrode through which Electric current flows into a polarized electrical device Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 Potassium (pəˈtæsiəm is a Chemical element. It has the symbol K (kalium from qalīy Atomic number 19 and Atomic mass 39 Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum A cathode is an Electrode through which (positive Electric current flows out of a polarized electrical device This flows continuously into a separate reactor ("denuder" or "secondary cell"), where it is usually converted back to mercury by reaction with water, producing hydrogen and sodium (or potassium) hydroxide at a commercially useful concentration (50% by weight). Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum Water is a common Chemical substance that is essential for the survival of all known forms of Life. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature Potassium hydroxide is the Inorganic compound with the formula K[[hydroxide OH]] In Chemistry, hydroxide is the most common name for the diatomic Anion OH− consisting of Oxygen and Hydrogen The mercury is then recycled to the primary cell. Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum

The mercury process is the least energy-efficient of the three main technologies (mercury, diaphragm and membrane) and there are also concerns about mercury emissions. Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum Pollution is the introduction of contaminants into an environment that causes instability disorder harm or discomfort to the physical systems or living organisms they are in

It is estimated that there are still around 100 mercury-cell plants operating worldwide. In Japan, mercury-based chloralkali production was virtually phased out by 1987 (except for the last two potassium chloride units shut down in 2003). For a topic outline on this subject see List of basic Japan topics. The Chemical compound potassium chloride (KCl is a Metal Halide salt composed of Potassium and Chlorine. In the United States, there will be only five mercury plants remaining in operation by the end of 2008. The United States of America —commonly referred to as the Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum In Europe, mercury cells accounted for 43% of capacity in 2006 and Western European producers have committed to closing or converting all remaining chloralkali mercury plants by 2020. Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum ^[9]

• Diaphragm cell electrolysis

In diaphragm cell electrolysis, an asbestos (or polymer-fiber) diaphragm separates a cathode and an anode, preventing the chlorine forming at the anode from re-mixing with the sodium hydroxide and the hydrogen formed at the cathode. In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current Asbestos is a group of Minerals with long thin fibrous Crystals The word "asbestos" (῾ἀσβεστος is derived from a Greek adjective A cathode is an Electrode through which (positive Electric current flows out of a polarized electrical device An anode is an Electrode through which Electric current flows into a polarized electrical device An anode is an Electrode through which Electric current flows into a polarized electrical device Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 A cathode is an Electrode through which (positive Electric current flows out of a polarized electrical device ^[10] This technology was also developed at the end of the nineteenth century. There are several variants of this process: the Le Sueur cell (1893), the Hargreaves-Bird cell (1901), the Gibbs cell (1908), and the Townsend cell (1904). ^[11][12] The cells vary in construction and placement of the diaphragm, with some having the diaphragm in direct contact with the cathode. A cathode is an Electrode through which (positive Electric current flows out of a polarized electrical device

The salt solution (brine) is continuously fed to the anode compartment and flows through the diaphragm to the cathode compartment, where the caustic alkali is produced and the brine is partially depleted. Salt is a Dietary mineral composed primarily of Sodium chloride that is essential for Animal life but toxic to most land plants In Chemistry, a solution is a Homogeneous Mixture composed of two or more substances Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl A cathode is an Electrode through which (positive Electric current flows out of a polarized electrical device In Chemistry, an alkali (from Arabic: Al-Qaly القلي القالي) is a basic, ionic salt of an Alkali metal Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl

As a result, diaphragm methods produce alkali that is quite dilute (about 12%) and of lower purity than do mercury cell methods. In Chemistry, an alkali (from Arabic: Al-Qaly القلي القالي) is a basic, ionic salt of an Alkali metal But diaphragm cells are not burdened with the problem of preventing mercury discharge into the environment. Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum They also operate at a lower voltage, resulting in an energy savings over the mercury cell method,^[12] but large amounts of steam are required if the caustic has to be evaporated to the commercial concentration of 50%. Electrical tension (or voltage after its SI unit, the Volt) is the difference of electrical potential between two points of an electrical Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. Evaporation is the process by which Molecules in a Liquid state (e

• Membrane cell electrolysis

Development of this technology began in the 1970s. The electrolysis cell is divided into two "rooms" by a cation permeable membrane acting as an ion exchanger. In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current 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 Ion exchange is an exchange of Ions between two Electrolytes or between an electrolyte Solution and a complex. Saturated sodium (or potassium) chloride solution is passed through the anode compartment, leaving at a lower concentration. For sodium chloride in the diet see Salt. Sodium chloride, also known as common salt, table salt, or Halite, is a The Chemical compound potassium chloride (KCl is a Metal Halide salt composed of Potassium and Chlorine. In Chemistry, a solution is a Homogeneous Mixture composed of two or more substances An anode is an Electrode through which Electric current flows into a polarized electrical device In Chemistry, concentration is the measure of how much of a given substance there is mixed with another substance ^[13] Sodium (or potassium) hydroxide solution is circulated through the cathode compartment, exiting at a higher concentration. Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature Potassium hydroxide is the Inorganic compound with the formula K[[hydroxide OH]] In Chemistry, hydroxide is the most common name for the diatomic Anion OH− consisting of Oxygen and Hydrogen In Chemistry, a solution is a Homogeneous Mixture composed of two or more substances A cathode is an Electrode through which (positive Electric current flows out of a polarized electrical device In Chemistry, concentration is the measure of how much of a given substance there is mixed with another substance A portion of the concentrated sodium hydroxide solution leaving the cell is diverted as product, while the remainder is diluted with deionized water and passed through the electrolysis apparatus again. In Chemistry, concentration is the measure of how much of a given substance there is mixed with another substance Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature In Chemistry, a solution is a Homogeneous Mixture composed of two or more substances Purified water is water from any source that is physically processed to remove impurities In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current

This method is more efficient than the diaphragm cell and produces very pure sodium (or potassium) hydroxide at about 32% concentration, but requires very pure brine. Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature Potassium hydroxide is the Inorganic compound with the formula K[[hydroxide OH]] In Chemistry, hydroxide is the most common name for the diatomic Anion OH− consisting of Oxygen and Hydrogen In Chemistry, concentration is the measure of how much of a given substance there is mixed with another substance Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl

• Other electrolytic processes

Although a much lower production scale is involved, electrolytic diaphragm and membrane technologies are also used industrially to recover chlorine from hydrochloric acid solutions, producing hydrogen (but no caustic alkali) as a co-product. Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 In Chemistry, an alkali (from Arabic: Al-Qaly القلي القالي) is a basic, ionic salt of an Alkali metal

Furthermore, electrolysis of fused chloride salts (Downs process) also enables chlorine to be produced, in this case as a by-product of the manufacture of metallic sodium or magnesium. In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current The Downs process is a method for the commercial preparation of metallic Sodium, in which molten NaCl is electrolyzed in a special apparatus called the Downs cell. The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24

Other methods

Before electrolytic methods were used for chlorine production, the direct oxidation of hydrogen chloride with oxygen or air was exercised in the Deacon process:

4 HCl + O₂ → 2 Cl₂ + 2 H₂O

This reaction is accomplished with the use of copper(II) chloride (CuCl₂) as a catalyst and is performed at high temperature (about 400 °C). Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five The Deacon process was a Secondary process used during the Manufacture of Alkalis (the initial end product was Sodium carbonate) by the Leblanc Copper(II chloride is the Chemical compound with the formula CuCl2 Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst The amount of extracted chlorine is approximately 80%. Due to the extremely corrosive reaction mixture, industrial use of this method is difficult and several pilot trials failed in the past. Nevertheless, recent developments are promising. Recently Sumitomo patented a catalyst for the Deacon process using ruthenium(IV) oxide (RuO₂). is one of the largest Keiretsus ' founded by Masatomo Sumitomo. Ruthenium(IV oxide ( Ru[[Oxygen O2]] is a black Chemical compound containing the rare metal Ruthenium and Oxygen. ^[14]

Another earlier process to produce chlorine was to heat brine with acid and manganese dioxide. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are Manganese(IV oxide is the Chemical compound MnO2 commonly called manganese dioxide.

2 NaCl + 2H₂SO₄ + MnO₂ → Na₂SO₄ + MnSO₄ + 2 H₂O + Cl₂

Using this process, chemist Carl Wilhelm Scheele was the first to isolate chlorine in a laboratory. Carl Wilhelm Scheele (9 December 1742 &ndash 21 May 1786 was a German - Swedish pharmaceutical chemist born in Stralsund, Western Pomerania, The manganese can be recovered by the Weldon process. Manganese (ˈmæŋgəniːz is a Chemical element, designated by the symbol Mn. The Weldon process is a process developed in 1870 by Walter Weldon for recovering Manganese dioxide for re-use in Chlorine manufacture ^[15]

Small amounts of chlorine gas can be made in the laboratory by putting concentrated hydrochloric acid in a flask with a side arm and rubber tubing attached. Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water Manganese dioxide is then added and the flask stoppered. Manganese(IV oxide is the Chemical compound MnO2 commonly called manganese dioxide. The reaction is not greatly exothermic. As chlorine is denser than air, it can be easily collected by placing the tube inside a flask where it will displace the air. Once full, the collecting flask can be stoppered.

Another method for producing small amounts of chlorine gas in a lab is by adding concentrated hydrochloric acid (typically about 5M) to sodium hypochlorite or sodium chlorate solution. Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water Sodium hypochlorite is a Chemical compound with the formula NaClO Sodium chlorate ( Na[[Chlorine Cl]] O 3 is an Oxidizing agent.

Industrial production

Large-scale production of chlorine involves several steps and many pieces of equipment. The description below is typical of a membrane plant. The plant also simultaneously produces sodium hydroxide (caustic soda) and hydrogen gas. Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 A typical plant consists of brine production/treatment, cell operations, chlorine cooling & drying, chlorine compression & liquefaction, liquid chlorine storage & loading, caustic handling, evaporation, storage & loading and hydrogen handling. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1

• Brine

Key to the production of chlorine is the operation of the brine saturation/treatment system. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl Maintaining a properly saturated solution with the correct purity is vital, especially for membrane cells. Many plants have a salt pile which is sprayed with recycled brine. Plants are living Organisms belonging to the kingdom Plantae. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl Others have slurry tanks that are fed raw salt. Salt is a Dietary mineral composed primarily of Sodium chloride that is essential for Animal life but toxic to most land plants

The raw brine is partially or totally treated with sodium hydroxide, sodium carbonate and a flocculant to reduce calcium, magnesium and other impurities. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature Sodium carbonate (also known as washing soda or soda ash), is a Sodium Salt of Carbonic acid. Flocculation is a process where a Solute comes out of Solution in the form of floc or flakes Calcium (ˈkælsiəm is the Chemical element with the symbol Ca and Atomic number 20 Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24 Impurities are Substances inside a confined amount of Liquid, Gas, or Solid, which differ from the Chemical composition of the material The brine proceeds to a large clarifier or a filter where the impurities are removed. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl Impurities are Substances inside a confined amount of Liquid, Gas, or Solid, which differ from the Chemical composition of the material The total brine is additionally filtered before entering ion exchangers to further remove impurities. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl Ion exchange is an exchange of Ions between two Electrolytes or between an electrolyte Solution and a complex. Impurities are Substances inside a confined amount of Liquid, Gas, or Solid, which differ from the Chemical composition of the material At several points in this process, the brine is tested for hardness and strength. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl Hardness refers to various properties of Matter in the Solid phase that give it high resistance to various kinds of shape change when Force

After the ion exchangers, the brine is considered pure, and is transferred to storage tanks to be pumped into the cell room. Ion exchange is an exchange of Ions between two Electrolytes or between an electrolyte Solution and a complex. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl Brine, fed to the cell line, is heated to the correct temperature to control exit brine temperatures according to the electrical load. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl If an electric circuit has a well-defined output terminal the circuit connected to this terminal (or its Input impedance) is the load. Brine exiting the cell room must be treated to remove residual chlorine and control pH levels before being returned to the saturation stage. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl pH is the measure of the acidity or alkalinity of a Solution. This can be accomplished via dechlorination towers with acid and sodium bisulfite addition. In Computer science, ACID ( Atomicity Consistency Isolation Durability) is a set of properties that guarantee that Database transactions are Sodium hydrogen sulfite or sodium bisulfite is a Chemical compound with the Chemical formula NaHSO3 Failure to remove chlorine can result in damage to the cells. Brine should be monitored for accumulation of bothchlorate anions and sulfate anions, and either have a treatment system in place, or purging of the brine loop to maintain safe levels, since chlorate anions can diffuse through the membranes and contaminate the caustic, while sulfate anions can damage the anode surface coating. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl The chlorate anion has the formula ClO3− In this case the Chlorine atom is in the +5 Oxidation state. The chlorate anion has the formula ClO3− In this case the Chlorine atom is in the +5 Oxidation state. An anode is an Electrode through which Electric current flows into a polarized electrical device

• Cell room

The building that houses the many electrolytic cells is usually called a cell room or cell house, although some plants are built outdoors. This building contains support structures for the cells, connections for supplying electrical power to the cells and piping for the fluids. Electric power is defined as the rate at which Electrical energy is transferred by an Electric circuit. Monitoring and control of the temperatures of the feed caustic and brine is done to control exit temperatures. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl Also monitored are the voltages of each cell which vary with the electrical load on the cell room that is used to control the rate of production. Electrical tension (or voltage after its SI unit, the Volt) is the difference of electrical potential between two points of an electrical If an electric circuit has a well-defined output terminal the circuit connected to this terminal (or its Input impedance) is the load. Monitoring and control of the pressures in the chlorine and hydrogen headers is also done via pressure control valves. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 The relief valve is a type of Valve used to control or limit the Pressure in a system or vessel which can build up by a process upset instrument or equipment failure

Direct current is supplied via a rectified power source. Direct current ( DC) is the unidirectional flow of Electric charge. A rectifier is an electrical device that converts Alternating current (AC to Direct current (DC a process known as rectification. Plant load is controlled by varying the current to the cells. As the current is increased, flow rates for brine and caustic and deionized water are increased, while lowering the feed temperatures. Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl Purified water is water from any source that is physically processed to remove impurities

• Cooling and drying

Chlorine gas exiting the cell line must be cooled and dried since the exit gas can be over 80°C and contains moisture that allows chlorine gas to be corrosive to iron piping. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 For other uses see Pipe. Within Industry, piping is a system of pipes used to convey Fluids ( Liquids and Cooling the gas allows for a large amount of moisture from the brine to condense out of the gas stream. Condensation is the change of the physical state of aggregation (or simply state of matter from gaseous phase into liquid phase Cooling also improves the efficiency of both the compression and the liquefaction stage that follows. Chlorine exiting is ideally between 18°C and 25°C. After cooling the gas stream passes through a series of towers with counter flowing sulfuric acid. Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid. These towers progressively remove any remaining moisture from the chlorine gas. After exiting the drying towers the chlorine is filtered to remove any remaining sulfuric acid. Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid.

• Compression and liquefaction

Several methods of compression may be used: liquid ring, reciprocating, or centrifugal. A liquid ring pump is a rotating positive displacement pump They are typically used as a Vacuum pump but can also be used as a Gas compressor. A reciprocating compressor is a compressor that uses Pistons driven by a Crankshaft to deliver gases at high pressure Centrifugal compressor, (sometimes referred to as radial compressors) are a special class of radial-flow work-absorbing Turbomachinery that includes pumps The chlorine gas is compressed at this stage and may be further cooled by inter- and after-coolers. After compression it flows to the liquefiers, where it is cooled enough to liquefy. Non condensible gases and remaining chlorine gas are vented off as part of the pressure control of the liquefaction systems. These gases are routed to a gas scrubber, producing sodium hypochlorite, or used in the production of hydrochloric acid (by combustion with hydrogen) or ethylene dichloride (by reaction with ethylene). Sodium hypochlorite is a Chemical compound with the formula NaClO Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Structure This Hydrocarbon has four Hydrogen Atoms bound to a pair of Carbon atoms that are connected by a Double bond.

• Storage and loading

Liquid chlorine is typically gravity-fed to storage tanks. Gravitation is a natural Phenomenon by which objects with Mass attract one another It can be loaded into rail or road tankers via pumps or padded with compressed dry gas.

• Caustic handling, evaporation, storage and loading

Caustic, fed to the cell room flows in a loop that is simultaneously bled off to storage with a part diluted with deionized water and returned to the cell line for strengthening within the cells. Purified water is water from any source that is physically processed to remove impurities The caustic exiting the cell line must be monitored for strength, to maintain safe concentrations. Too strong or too weak a solution may damage the membranes. In Chemistry, a solution is a Homogeneous Mixture composed of two or more substances Membrane cells typically produce caustic in the range of 30% to 33% by weight. The feed caustic flow is heated at low electrical loads to control its exit temperature. If an electric circuit has a well-defined output terminal the circuit connected to this terminal (or its Input impedance) is the load. Higher loads require the caustic to be cooled, to maintain correct exit temperatures. The caustic exiting to storage is pulled from a storage tank and may be diluted for sale to customers who require weak caustic or for use on site. Another stream may be pumped into a multiple effect evaporator set to produce commercial 50% caustic. A multiple-effect evaporator, as defined in Chemical engineering, is an apparatus for efficiently using the heat from Steam to evaporate water Rail cars and tanker trucks are loaded at loading stations via pumps.

• Hydrogen handling

Hydrogen produced may be vented unprocessed directly to the atmosphere or cooled, compressed and dried for use in other processes on site or sold to a customer via pipeline, cylinders or trucks. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 An atmosphere (from Greek ατμός - atmos, " Vapor " + σφαίρα - sphaira, " Sphere " Some possible uses include the manufacture of hydrochloric acid or hydrogen peroxide, as well as desulfurization of petroleum oils, or use as a fuel in boilers or fuel cells. Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water Hydrogen peroxide (H2O2 is a very pale blue liquid which appears colorless in a dilute solution slightly more Viscous than water Hydrodesulfurization (HDS is a Catalytic chemical process widely used to remove Sulfur (S from Natural gas and from refined petroleum products Petroleum ( L petroleum, from Greek πετρέλαιον, lit Fuel is any material that is burned or altered in order to obtain energy A boiler is a closed vessel in which Water or other Fluid is heated A fuel cell is an electrochemical conversion device It produces electricity from Fuel (on the Anode side and an oxidant (on the In Porsgrunn the byproduct is used for the hydrogen fueling station at hynor. Porsgrunn is a town and municipality in the county of Telemark, Norway. A hydrogen station is a storage or Filling station for Hydrogen, usually located along a road or Hydrogen highway, or at home as part of the Distributed The Hynor Hydrogen highway in Norway was established in 2003 and is part of the Scandinavian hydrogen highway partnership with hyfuture and hydrogen

• Energy consumption

Production of chlorine is extremely energy intensive. ^[16] Energy consumption per unit weight of product is not far below that for iron and steel manufacture^[17] and greater than for the production of glass^[18] or cement. ^[19]

Since electricity is an indispensable raw material for the production of chlorine, the energy consumption corresponding to the electrochemical reaction cannot be reduced. Electrochemistry is a branch of Chemistry that studies Chemical reactions which take place in a Solution at the interface of an electron conductor Energy savings arise primarily through applying more efficient technologies and reducing ancillary energy use.

Compounds

See also Chlorine compounds

For general references to the chloride ion (Cl⁻), including references to specific chlorides, see chloride. The chloride Ion is formed when the element Chlorine picks up one Electron to form an Anion (negatively-charged ion Cl&minus For other chlorine compounds see chlorate (ClO₃⁻), chlorite (ClO₂⁻), hypochlorite(ClO⁻), and perchlorate(ClO₄⁻), and chloramine (NH₂Cl). The chlorate anion has the formula ClO3− In this case the Chlorine atom is in the +5 Oxidation state. This discusses some chlorine compounds Chlorite is also a type of mineral see Chlorite group. The hypochlorite Ion is Cl[[Oxygen O]]− A hypochlorite compound is a Chemical compound containing this group with chlorine in Oxidation Perchlorates are the salts derived from Perchloric acid ( H[[chlorine Cl]] O4) Chloramine (monochloramine is a Chemical compound with the formula NH2Cl ^[20]

Other chlorine-containing compounds include:

• Fluorides: chlorine monofluoride (ClF), chlorine trifluoride (ClF₃), chlorine pentafluoride (ClF₅)
• Oxides: chlorine dioxide (ClO₂), dichlorine monoxide (Cl₂O), dichlorine heptoxide (Cl₂O₇)
• Acids: hydrochloric acid (HCl), chloric acid (HClO₃), and perchloric acid (HClO₄)

Oxidation states

Oxidation state	Name	Formula	Example compounds
−1	chlorides	Cl−	ionic chlorides, organic chlorides, hydrochloric acid
0	chlorine	Cl2	elemental chlorine
+1	hypochlorites	ClO−	sodium hypochlorite, calcium hypochlorite
+3	chlorites	ClO2−	sodium chlorite
+5	chlorates	ClO3−	sodium chlorate, potassium chlorate, chloric acid
+7	perchlorates	ClO4−	potassium perchlorate, perchloric acid,magnesium perchlorate organic perchlorates, ammonium perchlorate

Chlorine exists in all odd numbered oxidation states from −1 to +7, as well as the elemental state of zero. Chlorine monofluoride is a volatile Interhalogen compound with the Chemical formula ClF Chlorine trifluoride is the Chemical compound with the formula ClF3 Chlorine pentafluoride has formula ClF5 It was first synthesized in 1963 Chlorine dioxide is a Chemical compound with the formula ClO2 Dichlorine monoxide, Cl2O is a Chlorine oxide. Dichlorine monoxide is the Anhydride of Hypochlorous acid; it is related to Hypochlorites Dichlorine heptoxide is the Chemical compound with the formula Cl2O7 Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water Chloric acid, H[[Chlorine Cl]] O 3 is an Oxoacid of Chlorine, and the formal precursor of Chlorate salts Perchloric acid, HClO4 is an Oxoacid of Chlorine and is a colorless liquid soluble in water. The chloride Ion is formed when the element Chlorine picks up one Electron to form an Anion (negatively-charged ion Cl&minus Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water The hypochlorite Ion is Cl[[Oxygen O]]− A hypochlorite compound is a Chemical compound containing this group with chlorine in Oxidation Sodium hypochlorite is a Chemical compound with the formula NaClO Calcium hypochlorite is a Chemical compound with formula (2 It is widely used for Water treatment and as a Bleaching agent (bleaching This discusses some chlorine compounds Chlorite is also a type of mineral see Chlorite group. Sodium chlorite is a chemical compound used in the manufacture of Paper. The chlorate anion has the formula ClO3− In this case the Chlorine atom is in the +5 Oxidation state. Sodium chlorate ( Na[[Chlorine Cl]] O 3 is an Oxidizing agent. Potassium chlorate is a compound containing Potassium, Chlorine and Oxygen, with the chemical formula KClO3 Chloric acid, H[[Chlorine Cl]] O 3 is an Oxoacid of Chlorine, and the formal precursor of Chlorate salts Perchlorates are the salts derived from Perchloric acid ( H[[chlorine Cl]] O4) Potassium perchlorate, a Perchlorate salt with the chemical formula K[[chlorine Cl]] O4, is a strong oxidizer. Perchloric acid, HClO4 is an Oxoacid of Chlorine and is a colorless liquid soluble in water. Magnesium perchlorate is a powerful Oxidizing agent, with the formula Mg(ClO42 Ammonium perchlorate (AP is a Chemical compound with the formula N[[Hydrogen H]]4 Cl[[Oxygen O]]4 In Chemistry, the oxidation state is an indicator of the degree of Oxidation of an Atom in a Chemical compound. Progressing through the states, hydrochloric acid can be oxidized using manganese dioxide, or hydrogen chloride gas oxidized catalytically by air to form elemental chlorine gas. Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water Manganese(IV oxide is the Chemical compound MnO2 commonly called manganese dioxide. The solubility of chlorine in water is increased if the water contains dissolved alkali hydroxide. This is due to disproportionation:

Cl₂ + 2OH⁻ → Cl⁻ + ClO⁻ + H₂O

In hot concentrated alkali solution disproportionation continues:

2ClO⁻ → Cl⁻ + ClO₂⁻

ClO⁻ + ClO₂⁻ → Cl⁻ + ClO₃⁻

Sodium chlorate and potassium chlorate can be crystallized from solutions formed by the above reactions. Disproportionation or dismutation is used to describe two particular types of chemical reaction A chemical reaction of the type 2A → A' + A" where Sodium chlorate ( Na[[Chlorine Cl]] O 3 is an Oxidizing agent. Potassium chlorate is a compound containing Potassium, Chlorine and Oxygen, with the chemical formula KClO3 If their crystals are heated, they undergo the final disproportionation step.

4ClO₃⁻ → Cl⁻ + 3ClO₄⁻

This same progression from chloride to perchlorate can be accomplished by electrolysis. In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current The anode reaction progression is:^[21]

Reaction	Electrode potential
Cl− + 2OH− → ClO− + H2O + 2e−	+0. 89 volts
ClO− + 2OH− → ClO2− + H2O + 2e−	+0. 67 volts
ClO2− + 2OH− → ClO3− + H2O + 2e−	+0. 33 volts
ClO3− + 2OH− → ClO4− + H2O + 2e−	+0. 35 volts

Each step is accompanied at the cathode by

2H₂O + 2e⁻ → 2OH⁻ + H₂          −0. 83 volts

Applications and uses

Production of industrial and consumer products

Chlorine's principal applications are in the production of a wide range of industrial and consumer products. ^[22][23] For example, it is used in making plastics, solvents for dry cleaning and metal degreasing, textiles, agrochemicals and pharmaceuticals, insecticides, dyestuffs, etc.

Purification and disinfection

Chlorine is an important chemical for water purification, in disinfectants, and in bleach. Water purification is the process of removing contaminants and other harmful microorganisms from a raw water source Disinfectants are Antimicrobial agents that are applied to non-living objects to destroy Microorganisms, the process of which is known as disinfection. A bleach is a Chemical that removes color or whitens often via Oxidation. It is used (in the form of hypochlorous acid) to kill bacteria and other microbes in drinking water supplies and public swimming pools. Hypochlorous acid ( IUPAC name chloric(I acid) is a weak Acid with the Chemical formula HOCl The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have Water of sufficient quality to serve as drinking water is termed potable water whether it is used for drinking or not A swimming pool, swimming bath, wading pool, or simply a pool, is an artificially enclosed Body of water intended for Swimming or However, in most private swimming pools chlorine itself is not used, but rather sodium hypochlorite (household bleach), formed from chlorine and sodium hydroxide, or solid tablets of chlorinated isocyanurates. Sodium hypochlorite is a Chemical compound with the formula NaClO Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature Even small water supplies are now routinely chlorinated. ^[24] (See also chlorination)

Chemistry

Elemental chlorine is an oxidizer. Chlorination is the process of adding the element Chlorine to Water as a method of Water purification to make it fit for human consumption as An oxidizing agent or oxidising agent (also called an oxidant, oxidizer or oxidiser) can be defined as either a Chemical compound It undergoes halogen substitution reactions with lower halide salts. For example, chlorine gas bubbled through a solution of bromide or iodide anions oxidizes them to bromine and iodine respectively.

Like the other halogens, chlorine participates in free-radical substitution reactions with hydrogen-containing organic compounds. In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell This reaction is often – but not invariably – non-regioselective, and hence may result in a mixture of isomeric products. It is often difficult to control the degree of substitution as well, so multiple substitutions are common. If the different reaction products are easily separated, e. g. by distillation, substitutive free-radical chlorination (in some cases accompanied by concurrent thermal dehydrochlorination) may be a useful synthetic route. Industrial examples of this are the production of methyl chloride, methylene chloride, chloroform and carbon tetrachloride from methane, allyl chloride from propylene, and trichloroethylene and tetrachloroethylene from 1,2-dichloroethane. Chloromethane, also called Methyl chloride, R-40 or HCC 40 is a Chemical compound of the group of Organic compounds called Haloalkanes. Dichloromethane ( DCM) or methylene chloride is the Chemical compound with the formula CH2Cl2 Chloroform, also known as trichloromethane and methyl trichloride, is a Chemical compound with formula C[[Hydrogen H]] Cl Carbon tetrachloride, also known by many other names (see Table is the Organic compound with the formula CCl4 Allyl chloride is the Organic compound with the formula C[[Hydrogen H]]2=CHCH2 Cl. The Chemical compound trichloroethylene is a chlorinated Hydrocarbon commonly used as an industrial Solvent. Tetrachloroethylene, also known under its systematic name tetrachloroethene and as perchloroethylene, perchloroethene, perc, and PCE

Like the other halides, chlorine undergoes electrophilic additions reactions, most notably, the chlorination of alkenes and aromatic compounds with a Lewis acid catalyst. Organic chlorine compounds tend to be less reactive in nucleophilic substitution reactions than the corresponding bromine or iodine derivatives, but they tend to be cheaper. They may be activated for reaction by substituting with a tosylate group, or by the use of a catalytic amount of sodium iodide. Sodium iodide is a white Crystalline Salt with Chemical formula Na[[Iodine I]] used in radiation detection treatment of Iodine deficiency

Chlorine is used extensively in organic and inorganic chemistry as an oxidizing agent and in substitution reactions because chlorine often imparts many desired properties to an organic compound, due to its electronegativity. Organic chemistry is a discipline within Chemistry which involves the scientific study of the structure properties composition reactions, and preparation Inorganic chemistry is the branch of Chemistry concerned with the properties and behavior of Inorganic compounds This field covers all Chemical compounds In a substitution reaction, a Functional group in a particular Chemical compound is replaced by another group An organic compound is any member of a large class of Chemical compounds whose Molecules contain Carbon.

Chlorine compounds are used as intermediates in the production of a number of important commercial products that do not contain chlorine. Examples are: polycarbonates, polyurethanes, silicones, polytetrafluoroethylene, carboxymethyl cellulose and propylene oxide. A polyurethane, commonly abbreviated PU, is any Polymer consisting of a chain of organic units joined by urethane links Silicones are largely inert compounds with a wide variety of forms and uses In Chemistry, poly(tetrafluoroethene or poly(tetrafluoroethylene ( PTFE) is a synthetic Fluoropolymer which finds numerous applications Carboxymethyl cellulose, or CMC, is a Cellulose derivative with carboxymethyl groups (-CH2-COOH bound to some of the Hydroxyl groups Propylene oxide is a highly toxic flammable Chemical compound.

Use as a weapon

• World War I

Main article: Poison gas in World War I

Chlorine gas, also known as bertholite, was first used as a weapon in World War I by Germany on April 22, 1915 in the Second Battle of Ypres. The use of poison gas in World War I was a major military innovation Chemical warfare involves using the toxic properties of Chemical substances to kill injure or incapacitate an enemy. World War I (abbreviated WWI; also known as the First World War, the Great War, and the War to End All Events 1500 - Portuguese Navigator Pedro Álvares Cabral becomes the first European to sight Brazil. Year 1915 ( MCMXV) was a Common year starting on Friday (link will display the full calendar of the Gregorian calendar (or a Common year The Second Battle of Ypres was the first time Germany used poison gas on a large scale on the Western Front in World War I and the first time As described by the soldiers it had a distinctive smell of a mixture between pepper and pineapple. It also tasted metallic and stung the back of the throat and chest. Chlorine can react with water in the mucosa of the lungs to form hydrochloric acid, an irritant which can be lethal. Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water The damage done by chlorine gas can be prevented by a gas mask which makes the deaths by chlorine gas much lower then those of other chemical weapons. It was pioneered by a German scientist later to be a Nobel laureate, Fritz Haber of the Kaiser Wilhelm Institute in Berlin, in collaboration with the German chemical conglomerate IG Farben, who developed methods for discharging chlorine gas against an entrenched enemy. Fritz Haber (9 December 1868 &ndash 29 January 1934 was a German chemist, who received the Nobel Prize in Chemistry in 1918 for his development for IG Farben (short for Interessen-Gemeinschaft Farbenindustrie AG, "syndicate of dyestuff corporations" and also called I A trench is a type of excavation or depression in the ground Trenches are generally defined by being deeper than they are wide (as opposed to a wider Gully or Ditch It is alleged that Haber's role in the use of chlorine as a deadly weapon drove his wife, Clara Immerwahr, to suicide. Clara Immerwahr ( June 21, 1870 &ndash May 2, 1915) was a German Chemist and the wife of Fritz Haber, who After its first use, chlorine was utilized by both sides as a chemical weapon, but it was soon replaced by the more deadly gases phosgene and mustard gas. Phosgene is the Chemical compound with the formula COCl2 This colorless gas gained infamy as a Chemical weapon during World War I The sulfur mustards, of which mustard gas ( Bis (2-chloroethyl sulfide is a member are a class of related Cytotoxic, Vesicant Chemical ^[25]

• Iraq War

Main article: 2007 chlorine bombings in Iraq

Chlorine gas has also been used by insurgents in the Iraq War as a chemical weapon to terrorize the local population and coalition forces. See also Iraq War Chlorine bombings in Iraq began as early as October 2006 when insurgents in Al Anbar province started using Chlorine gas in conjunction The Iraq War, also known as the Second Gulf War, the Occupation of Iraq, or the War in Iraq, is an ongoing Military campaign This article is about the pressure bomb For the improvised explosive devices used in Iraq refer to Chlorine bombings in Iraq. On March 17, 2007, for example, three chlorine filled trucks were detonated in the Anbar province killing 2 and sickening over 350. Events 45 BC - In his last victory Julius Caesar defeats the Pompeian forces of Titus Labienus and Pompey the Younger Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. ^[26] Other chlorine bomb attacks resulted in higher death tolls, with more than 30 deaths on two separate occasions. ^[27] Most of the deaths were caused by the force of the explosions rather than the effects of chlorine, since the toxic gas is readily dispersed and diluted in the atmosphere by the blast. The Iraqi authorities have tightened up security for chlorine, which is essential for providing safe drinking water for the population.

Other uses

Chlorine is used in the manufacture of numerous organic chlorine compounds, the most significant of which in terms of production volume are 1,2-dichloroethane and vinyl chloride, intermediates in the production of PVC. Vinyl chloride is the Organic compound with the formula CH2CHCl Other particularly important organochlorines are methyl chloride, methylene chloride, chloroform, vinylidene chloride, trichloroethylene, perchloroethylene, allyl chloride, epichlorohydrin, chlorobenzene, dichlorobenzenes and trichlorobenzenes. Chloromethane, also called Methyl chloride, R-40 or HCC 40 is a Chemical compound of the group of Organic compounds called Haloalkanes. Dichloromethane ( DCM) or methylene chloride is the Chemical compound with the formula CH2Cl2 Chloroform, also known as trichloromethane and methyl trichloride, is a Chemical compound with formula C[[Hydrogen H]] Cl The Chemical compound trichloroethylene is a chlorinated Hydrocarbon commonly used as an industrial Solvent. Tetrachloroethylene, also known under its systematic name tetrachloroethene and as perchloroethylene, perchloroethene, perc, and PCE Allyl chloride is the Organic compound with the formula C[[Hydrogen H]]2=CHCH2 Cl. Epichlorohydrin is a reactive Organic compound. It is an Epoxide and an Organochloride. Chlorobenzene is an Aromatic Organic compound with the chemical formula C6H5Cl Trichlorobenzene may refer to any of three Isomeric chlorinated derivatives of Benzene with the molecular formula C6H3Cl3

Chlorine is also used in the production of chlorates and in bromine extraction. The chlorate anion has the formula ClO3− In this case the Chlorine atom is in the +5 Oxidation state.

History

Chlorine was discovered in 1774 by Swedish chemist Carl Wilhelm Scheele, who called it dephlogisticated marine acid (see phlogiston theory) and mistakenly thought it contained oxygen. Carl Wilhelm Scheele (9 December 1742 &ndash 21 May 1786 was a German - Swedish pharmaceutical chemist born in Stralsund, Western Pomerania, The phlogiston theory (from the Ancient Greek φλογιστόν phlŏgistón "burning up" from φλόξ phlóx "fire" first stated Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Scheele isolated chlorine by reacting MnO₂ with HCl. Manganese(IV oxide is the Chemical compound MnO2 commonly called manganese dioxide. Hydrochloric acid is the Solution of Hydrogen chloride ( H[[Chlorine Cl]] in water

4 HCl + MnO₂ → MnCl₂ + 2 H₂O + Cl₂

Scheele observed several of the properties of chlorine. The bleaching effect on litmus and the deadly effect on insects additional to the yellow green colour and the smell similar to aqua regia. Aqua regia ( Latin for royal water) is a highly corrosive fuming yellow or red solution Chlorine was given its current name in 1810 by Sir Humphry Davy, who insisted that it was in fact an element. Sir Humphry Davy 1st Baronet FRS MRIA (17 December 1778 &ndash 29 May 1829 was a British Chemist and inventor

Safety

Chlorine is a toxic gas that irritates the respiratory system. Because it is heavier than air, it tends to accumulate at the bottom of poorly ventilated spaces. Chlorine gas is a strong oxidizer, which may react with flammable materials. ^[28]

Chlorine is detectable in concentrations of as low as 1 ppm. Coughing and vomiting may occur at 30 ppm and lung damage at 60 ppm. About 1000 ppm can be fatal after a few deep breaths of the gas. ^[2] Breathing lower concentrations can aggravate the respiratory system, and exposure to the gas can irritate the eyes.

Never use ABC Dry Chemical to fight a chlorine fire, the resulting chemical reaction with the ammonium phosphate will release toxic gases and/or result in an explosion. ABC or Multi-Purpose dry chemical is a dry chemical extinguishing agent Water fogs or CAFS should be used to extinguish the material. A Compressed Air Foam System for hand hose, abbreviated CAFS, is a system used in Firefighting to deliver Fire retardant foam for the purpose of extinguishing ^[28]

The number of people allergic to chlorine is very small. People who are allergic to chlorine cannot drink tap water, bathe in tap water or swim in pools. Dechlorinating bath salts are used to neutralize the chlorine in bath water. The term bath salts refers to a range of water-soluble usually inorganic solid products designed to be added to a bath either to improve cleaning provide a medical improvement Otherwise, fresh water is boiled and cooled.

Chlorine cracking

The element is widely used for purifying water owing to its powerful oxidising properties, especially potable water supplies and water used in swimming pools. A swimming pool, swimming bath, wading pool, or simply a pool, is an artificially enclosed Body of water intended for Swimming or However, some polymers are sensitive to attack, including acetal resin and polybutene. A polymer is a large Molecule ( Macromolecule) composed of repeating Structural units typically connected by Covalent Chemical bonds Polyoxymethylene (POM in the USA also commonly known under DuPont 's brand name Delrin, is an Engineering plastic, a Polymer with the chemical Both materials were used in hot and cold water domestic supplies, and stress corrosion cracking cause widespread failures in the USA in the 1980s and 90's. Fracture mechanics --> Stress corrosion cracking ( SCC) is the unexpected sudden failure of normally Ductile metals or tough Thermoplastics One example shows an acetal joint in a water supply system, which when it fractured, caused substantial physical damage to computers in the labs below the supply. The cracks started at injection moulding defects in the joint and grew slowly until finally triggered. Injection molding (British moulding The fracture surface shows iron and calcium salts which were deposited in the leaking joint from the water supply before failure

See also

• Chloride
• Polymer degradation

References

External links

• Chlorine Institute - Trade association and lobby group representing the interests of the chlorine industry
• Chlorine Online - Chlorine Online is an information resource produced by Eurochlor - the business association of the European chlor-alkali industry
• Computational Chemistry Wiki
• Chlorine Production Using Mercury, Environmental Considerations and Alternatives
• National Pollutant Inventory - Chlorine
• National Institute for Occupational Safety and Health - Chlorine Page

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