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| − | {| align="right" border="1" cellspacing="0" cellpadding="3" style="margin: 0 0 0 0.5em; background: #FFFFFF; border-collapse: collapse; border-color: #C0C090;"
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| − | ! {{chembox header}} | Hydrochloric acid
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| − | |-
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| − | | align="center" colspan="2" bgcolor="111715" | [[Image:Hydrochloric acid 05.jpg|130px|Hydrochloric acid]]
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| − | |-
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| − | ! {{chembox header}} | General
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| − | |-
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| − | | [[IUPAC nomenclature|Systematic name]]
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| − | | Hydrochloric acid
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| − | |-
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| − | | Other names
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| − | | Muriatic acid, Spirit of salt
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| − | |-
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| − | | [[Chemical formula|Molecular formula]]
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| − | | HCl in [[water (molecule)|water]] (H<sub>2</sub>O)
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| − | |-
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| − | | [[Molar mass]]
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| − | | 36.46 g/mol (HCl)
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| − | |-
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| − | | Appearance
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| − | | Clear colorless to<br />light-yellow liquid
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| − | |-
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| − | | [[CAS registry number|CAS number]]
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| − | | [7647-01-0]
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| − | |-
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| − | ! {{chembox header}} | Properties
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| − | |-
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| − | | [[Density]], [[Phase (matter)|phase]]
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| − | | 1.18 g/cm³,<br />37% solution.
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| − | |-
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| − | | [[Soluble|Solubility]] in [[Water (molecule)|water]]
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| − | | Fully miscible.
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| − | |-
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| − | | [[Melting point]]
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| − | | −26 °C (247 K)<br />38% solution.
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| − | |-
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| − | | [[Boiling point]]
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| − | | 110 °C (383 K),<br />20.2% solution;<br /> 48 °C (321 K),<br />38% solution.
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| | | | |
| − | |-
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| − | | [[Acid dissociation constant|Acid dissociation<br />constant]] p''K''<sub>a</sub>
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| − | | −8.0
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| − | |-
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| − | | [[Viscosity]]
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| − | | 1.9 [[pascal second|mPa·s]] at 25 °C,<br />31.5% solution
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| − | |-
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| − | ! {{chembox header}} | Hazards
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| − | |-
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| − | | [[Material safety data sheet|MSDS]]
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| − | | [http://ptcl.chem.ox.ac.uk/MSDS/HY/hydrochloric_acid.html External MSDS]
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| − | |-
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| − | | [[NFPA 704]]
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| − | | {{ NFPA 704 | Health=3 | Reactivity=1 }}<br/>32–38% solution
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| − | | Main [[Worker safety and health|Hazard]]s
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| − | | Highly corrosive.
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| − | |-
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| − | | [[Flash point]]
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| − | | Non-flammable.
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| − | |-
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| − | | [[Risk and Safety Statements|R/S statement]]
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| − | | {{R34}}, {{R37}},<br />{{S26}}, {{S36}}, {{S45}}
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| − | |-
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| − | | [[RTECS]] number
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| − | | MW4025000
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| − | ! {{chembox header}} | [[Hydrochloric acid (data page)|Supplementary data page]]
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| − | |-
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| − | | [[Hydrochloric acid (data page)#Structure and properties|Structure and<br />properties]]
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| − | | [[Refractive index|''n'']], [[Dielectric constant|''ε<sub>r</sub>'']], etc.
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| − | |-
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| − | | [[Hydrochloric acid (data page)#Thermodynamic properties|Thermodynamic<br />data]]
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| − | | Phase behavior<br/>Solid, liquid, gas
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| − | |-
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| − | | [[Hydrochloric acid (data page)#Spectral data|Spectral data]]
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| − | | [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[Nuclear magnetic resonance|NMR]], [[Mass spectrometry|MS]]
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| − | |-
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| − | ! {{chembox header}} | Related compounds
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| − | |-
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| − | | Other [[Ion|anion]]s
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| − | | [[Hydrofluoric acid|HF]], [[Hydrobromic acid|HBr]], [[Hydroiodic acid|HI]]
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| − | |-
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| − | | Other [[Ion|cation]]s
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| − | | N/a
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| − | |-
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| − | | Related [[acid]]s
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| − | | [[Hydrobromic acid]]<br />[[Hydrofluoric acid]]<br />[[Hydroiodic acid]]<br />[[Sulfuric acid]]
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| − | |-
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| − | | {{chembox header}} | <small>Except where noted otherwise, data are given for<br/> materials in their [[standard state|standard state (at 25 °C, 100 kPa)]]<br />[[wikipedia:Chemical infobox|Infobox disclaimer and references]]</small>
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| − | |-
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| − | |}
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| − |
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| − | The [[chemical compound]] '''hydrochloric acid''' (or '''muriatic acid''') is the [[aqueous]] ([[water]]-based) [[solution]] of [[hydrogen chloride]] gas ([[Hydrogen|H]][[Chlorine|Cl]]). This [[strong acid]] is highly [[corrosive]] and must be handled with appropriate [[safety]] precautions. It is the major component of [[gastric acid]]. It is an important industrial chemical for many applications, including the large-scale production of [[organic chemistry|organic]] compounds, such as [[vinyl chloride]] for [[polyvinyl chloride]] (PVC) [[plastic]], and smaller-scale applications, such as production of [[gelatin]] and other [[cooking|ingredients in food]], and [[leather]] processing. About 20 million metric tons of HCl gas are produced annually.
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| − |
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| − | ==History==
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| − |
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| − | Hydrochloric acid was first discovered around 800 C.E. by the [[Alchemy (islam)|alchemist]] [[Geber|Jabir ibn Hayyan]] (Geber), by mixing [[Sodium chloride|common salt]] with [[vitriol]] ([[sulfuric acid]]). Jabir discovered many important chemicals, and recorded his findings in over 20 books, which carried his chemical knowledge of hydrochloric acid and other basic chemicals for hundreds of years. Jabir's invention of the gold-dissolving [[aqua regia]], consisting of hydrochloric acid and [[nitric acid]], was of great interest to alchemists searching for the [[philosopher's stone]].
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| − | [[Image:Jabir ibn Hayyan.jpg|thumb|left|200px|Jabir ibn Hayyan, medieval manuscript drawing.]]
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| − | In the [[Middle Ages]], hydrochloric acid was known to European alchemists as ''spirit of salt'' or ''acidum salis.'' Gaseous HCl was called ''marine acid air.'' The old (pre-[[systematic name|systematic]]) name ''muriatic acid'' has the same origin (''muriatic'' means "pertaining to brine or salt"), and this name is still sometimes used. Notable production was recorded by [[Basilius Valentinus]], the alchemist-[[Canon (priest)|canon]] of the [[Benedictine]] [[priory]] Sankt Peter in [[Erfurt|Erfurt, Germany]] in the fifteenth century. In the seventeenth century, [[Johann Rudolf Glauber]] from [[Karlstadt am Main|Karlstadt am Main, Germany]] used sodium chloride salt and sulfuric acid for the preparation of [[sodium sulfate]] in the [[Mannheim process]], releasing [[hydrogen chloride]] gas. [[Joseph Priestley]] of [[Leeds, England]] prepared pure hydrogen chloride in 1772, and in 1818 [[Humphry Davy]] of [[Penzance, England]] proved that the chemical composition included [[hydrogen]] and [[chlorine]].
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| − | During the [[Industrial Revolution]] in Europe, demand for [[alkaline]] substances such as [[soda ash]] increased, and the new industrial soda process by [[Nicolas Leblanc]] ([[Issoudun|Issoundun, France]]) enabled cheap, large-scale production. In the [[Leblanc process]], salt is converted to soda ash using sulfuric acid, limestone, and coal. Hydrogen chloride is released as a by-product. Until the [[Alkali Act]] of 1863, excess HCl was vented to the air. After passage of the act, soda ash producers were obliged to absorb the waste gas in water, producing hydrochloric acid on an industrial scale.
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| − | When early in the twentieth century the Leblanc process was effectively replaced by the [[Solvay process]] without the hydrochloric acid by-product, hydrochloric acid was already fully settled as an important chemical in numerous applications. The commercial interest initiated other production methods that are still used today, as described below. Today, most hydrochloric acid is made by absorbing hydrogen chloride from [[Hydrochloric acid#Production|industrial organic compounds production]].
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| − | Hydrochloric acid is listed as a Table II precursor under the 1988 [[Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances]] because of its use in the production of drugs such as [[heroin]], [[cocaine]], and [[methamphetamine]].<ref name='incb'> [[International Narcotics Control Board]] [http://www.incb.org/pdf/e/list/red.pdf List of precursors and chemicals frequently used in the illicit manufacture of narcotic drugs and pychotropic substances under international control].Retrieved March 24, 2008. </ref>
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| − |
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| − | ==Chemistry==
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| − | [[Image:Titration.gif|frame|left|70px|Acid titration.]]
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| − |
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| − | Hydrogen chloride (HCl) is a [[monoprotic acid]], which means that each molecule can [[Dissociation (chemistry)|dissociate]] (ionize) only once to release one H<sup>+</sup> ion (a single [[proton]]). In aqueous hydrochloric acid, the H<sup>+</sup> joins a water molecule to form a [[hydronium]] ion, H<sub>3</sub>O<sup>+</sup>:
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| − | :: HCl + H<sub>2</sub>O {{unicode|⇌}} H<sub>3</sub>O<sup>+</sup> + Cl<sup>−</sup>
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| − |
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| − | [[Image:Hydrogen-chloride-3D-vdW-labelled.png|200px|thumb|Molecular model of hydrogen chloride.]]
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| − | The other ion formed is Cl<sup>−</sup>, the [[Chloride|chloride ion]]. Hydrochloric acid can therefore be used to prepare salts called ''chlorides,'' such as [[sodium chloride]]. Hydrochloric acid is a [[strong acid]], since it is fully dissociated in water.
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| − |
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| − | Monoprotic acids have one [[acid dissociation constant]], K<sub>a</sub>, which indicates the level of dissociation in water. For a strong acid like HCl, the K<sub>a</sub> is large. Theoretical attempts to assign a K<sub>a</sub> to HCl have been made.<ref name='chembuddy'> [http://www.chembuddy.com/?left=BATE&right=dissociation_constants Dissociation constants pKa and pKb] ''ChemBuddy.com''.Retrieved March 24, 2008. </ref> When chloride salts such as NaCl are added to aqueous HCl they have practically no effect on [[pH]], indicating that Cl<sup>−</sup> is an exceedingly weak [[conjugate base]] and that HCl is fully dissociated in aqueous solution. For intermediate to strong solutions of hydrochloric acid, the assumption that H<sup>+</sup> [[molarity]] (a unit of [[concentration]]) equals HCl molarity is excellent, agreeing to four significant digits.
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| − | Of the seven common strong acids in chemistry, all of them [[inorganic]], hydrochloric acid is the monoprotic acid least likely to undergo an interfering [[redox|oxidation-reduction]] reaction. It is one of the least hazardous strong acids to handle; despite its acidity, it produces the less reactive and non-toxic chloride ion. Intermediate strength hydrochloric acid solutions are quite stable, maintaining their concentrations over time. These attributes, plus the fact that it is available as a pure [[reagent]], mean that hydrochloric acid makes an excellent acidifying reagent and acid titrant (for determining the amount of an unknown quantity of [[base (chemistry)|base]] in [[titration]]). Strong acid titrants are useful because they give more distinct endpoints in a titration, making the titration more precise. Hydrochloric acid is frequently used in [[chemical analysis]] and to digest samples for analysis. Concentrated hydrochloric acid will dissolve some [[metal]]s to form oxidized metal chlorides and [[hydrogen]] gas. It will produce metal chlorides from basic compounds such as [[calcium carbonate]] or [[copper(II) oxide]]. It is also used as a simple acid [[catalyst]] for some [[chemical reaction]]s.
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| − |
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| − | ===Physical properties===
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| − | The [[physical property|physical properties]] of hydrochloric acid, such as [[boiling point|boiling]] and [[melting points]], [[density]], and [[pH]] depend on the [[concentration]] or [[molarity]] of HCl in the acid solution. They can range from those of water at 0 percent HCl to values for fuming hydrochloric acid at over 40 percent HCl.
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| − | <center>
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| − | {| border="1" cellspacing="0" cellpadding="3" style="background: #ffffff; border-collapse: collapse; margin-left: auto; margin-right: auto; margin-top: 0.5em; margin-bottom: 0.5em;"
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| − | |- bgcolor="#ffdead" align="center"
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| − | | '''[[Concentration|Conc. (w/w)]] '''<br />c : kg HCl/kg
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| − | | '''Conc. (w/v)'''<br />c : kg HCl/m<sup>3</sup>
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| − | | '''Conc. '''<br />'''[[Baum%C3%A9_scale|Baumé]]'''<br />
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| − | | '''[[Density]]'''<br />ρ : kg/l
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| − | | '''[[Molarity]]'''<br />M
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| − | | ''' [[pH]] '''<br />
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| − | | '''[[Viscosity]]'''<br />η : mPa·s
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| − | | '''[[Specific heat capacity|Specific<br />heat]]'''<br />s : kJ/(kg·K)
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| − | | '''[[Vapor pressure|Vapor<br />pressure]]'''<br />P<sub>HCl</sub> : Pa
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| − | | '''[[Boiling point|Boiling<br />point]]'''<br />b.p.
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| − | | '''[[Melting point|Melting<br />point]]'''<br />m.p.
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| − | |- align="center"
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| − | | bgcolor="#ffdead" | 10% || 104.80 || 6.6 || 1.048 || 2.87 M || -0.5 || 1.16 || 3.47 || 0.527 || 103 °C || -18 °C
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| − | |- align="center"
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| − | | bgcolor="#ffdead" | 20% || 219.60 || 13 || 1.098 || 6.02 M || -0.8 || 1.37 || 2.99 || 27.3 || 108 °C || -59 °C
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| − | |- align="center"
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| − | | bgcolor="#ffdead" | 30% || 344.70 || 19 || 1.149 || 9.45 M || -1.0 || 1.70 || 2.60 || 1,410 || 90 °C || -52 °C
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| − | |- align="center"
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| − | | bgcolor="#ffdead" | 32% || 370.88 || 20 || 1.159 || 10.17 M || -1.0 || 1.80 || 2.55 || 3,130 || 84 °C || -43 °C
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| − | |- align="center"
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| − | | bgcolor="#ffdead" | 34% || 397.46 || 21 || 1.169 || 10.90 M || -1.0 || 1.90 || 2.50 || 6,733 || 71 °C || -36 °C
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| − | |- align="center"
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| − | | bgcolor="#ffdead" | 36% || 424.44 || 22 || 1.179 || 11.64 M || -1.1 || 1.99 || 2.46 || 14,100 || 61 °C || -30 °C
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| − | |- align="center"
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| − | | bgcolor="#ffdead" | 38% || 451.82 || 23 || 1.189 || 12.39 M || -1.1 || 2.10 || 2.43 || 28,000 || 48 °C || -26 °C
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| − | |}
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| − | <small>The reference [[temperature]] and [[pressure]] for the above table are 20 °C and 1 atmosphere (101 kPa).</small></center>
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| − | Hydrochloric acid as the binary (two-component) mixture of HCl and H<sub>2</sub>O has a constant-boiling [[azeotrope]] at 20.2 percent HCl and 108.6 °C (227 °F). There are four constant-[[crystallization]] [[eutectic|eutectic points]] for hydrochloric acid, between the [[crystal]] form of HCl·H<sub>2</sub>O (68 percent HCl), HCl·2H<sub>2</sub>O (51 percent HCl), HCl·3H<sub>2</sub>O (41 percent HCl), HCl·6H<sub>2</sub>O (25 percent HCl), and [[ice]] (0 percent HCl). There is also a metastable eutectic point at 24.8 percent between ice and the HCl·3H<sub>2</sub>O crystallization
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| − |
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| − | == Production ==
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| − | {{main|hydrogen chloride}}
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| − | Hydrochloric acid is prepared by dissolving hydrogen chloride in water. Hydrogen chloride can be generated in many ways, and thus several different precursors to hydrochloric acid exist. The large scale [[mass production|production]] of hydrochloric acid is almost always integrated with other industrial scale [[chemical industry|chemicals production]].
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| − | ===Industrial market===
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| − | Hydrochloric acid is produced in solutions up to 38 percent HCl (concentrated grade). Higher [[concentration]]s up to just over 40 percent are chemically possible, but the [[evaporation]] rate is then so high that [[storage]] and handling need extra precautions, such as [[pressure]] and low [[temperature]]. Bulk industrial-grade is therefore 30 percent to 34 percent, optimized for effective [[transport]] and limited product loss by HCl [[vapor]]s. Solutions for household purposes, mostly cleaning, are typically 10 percent to 12 percent, with strong recommendations to dilute before use.
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| − | Major producers worldwide include [[Dow Chemical Company|Dow Chemical]] at 2 million metric tons annually (2 Mt/year), calculated as HCl gas, and [[Formosa Plastics|FMC]], [[Georgia Gulf|Georgia Gulf Corporation]], [[Tosoh|Tosoh Corporation]], [[Akzo Nobel]], and [[Tessenderlo]] at 0.5 to 1.5 Mt/year each. Total world production, for comparison purposes expressed as HCl, is estimated at 20 Mt/year, with 3 Mt/year from direct synthesis, and the rest as secondary product from organic and similar syntheses. By far, most of all hydrochloric acid is consumed captively by the producer. The open world market size is estimated at 5 Mt/year.
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| − | ==Applications==
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| − | Hydrochloric acid is a strong inorganic acid that is used in many industrial processes. The application often determines the required product quality.
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| − | ===Regeneration of ion exchangers===
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| − | An important application of high-quality hydrochloric acid is the regeneration of [[ion exchange resin]]s. [[Ion exchange|Cation exchange]] is widely used to remove [[ion]]s such as Na<sup>+</sup> and Ca<sup>2+</sup> from [[aqueous]] solutions, producing [[mineral|demineralized]] water.
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| − | :: Na<sup>+</sup> is replaced by H<sub>3</sub>O<sup>+</sup>
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| − | :: Ca<sup>2+</sup> is replaced by 2 H<sub>3</sub>O<sup>+</sup>
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| − | Ion exchangers and demineralized water are used in all chemical industries, [[drinking water]] production, and many [[food]] industries.
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| − |
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| − | ===pH Control and neutralization===
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| − | A very common application of hydrochloric acid is to regulate the [[basicity]] ([[pH]]) of solutions.
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| − | :: OH<sup>−</sup> + HCl → H<sub>2</sub>O + Cl<sup>−</sup>
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| − | In industry demanding purity (food, pharmaceutical, drinking water), high-quality hydrochloric acid is used to control the pH of process water streams. In less-demanding industry, technical-quality hydrochloric acid suffices for [[acid-base reaction theories|neutralizing]] waste streams and [[swimming pool]] treatment.
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| − | ===Pickling of steel===
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| − | [[Pickling (metal)|Pickling]] is an essential step in [[metal]] surface treatment, to remove [[rust]] or [[iron oxide]] scale from [[iron]] or [[steel]] before subsequent processing, such as [[extrusion]], [[rolling]], [[galvanization|galvanizing]], and other techniques. Technical-quality HCl at typically 18 percent concentration is the most commonly-used pickling agent for the pickling of carbon steel grades.
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| − |
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| − | :: Fe<sub>2</sub>O<sub>3</sub> + Fe + 6 HCl → 3 FeCl<sub>2</sub> + 3 H<sub>2</sub>O
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| − | The [[spent acid]] has long been re-used as [[ferrous chloride]] solutions, but high [[heavy metals|heavy-metal]] levels in the pickling liquor has decreased this practice.
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| − | In recent years, the steel pickling industry has however developed [[hydrochloric acid regeneration]] processes, such as the spray roaster or the fluidized bed HCl regeneration process, which allow the recovery of HCl from spent pickling liquor. The most common regeneration process is the [[pyrohydrolysis]] process, applying the following formula:
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| − | :: 4 FeCl<sub>2</sub> + 4 H<sub>2</sub>O + O<sub>2</sub> → 8 HCl+ 2 Fe<sub>2</sub>O<sub>3</sub>
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| − | By recuperation of the spent acid, a closed acid loop is established. The ferric oxide by product of the regeneration process is a valuable by-product, used in a variety of secondary industries.
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| − | HCl is not a common pickling agent for stainless steel grades.
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| − |
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| − | ===Production of inorganic compounds===
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| − | Numerous products can be produced with hydrochloric acid in normal [[Acid-base reaction theories|acid-base reactions]], resulting in [[inorganic]] compounds. These include water treatment chemicals such as [[iron(III) chloride]] and [[Aluminium chlorohydrate|polyaluminium chloride (PAC)]].
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| − |
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| − | :: Fe<sub>2</sub>O<sub>3</sub> + 6 HCl → 2 FeCl<sub>3</sub> + 3 H<sub>2</sub>O
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| − |
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| − | Both iron(III) chloride and PAC are used as [[flocculation]] and coagulation agents in [[wastewater#treatment|wastewater treatment]], [[drinking water]] production, and [[paper]] production.
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| − |
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| − | Other inorganic compounds produced with hydrochloric acid include road application salt [[calcium chloride]], [[nickel(II) chloride]] for [[electroplating]], and [[zinc chloride]] for the [[galvanizing]] industry and [[battery (electricity)|battery]] production.
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| − | ===Production of organic compounds===
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| − | The largest hydrochloric acid consumption is in the production of [[organic compounds]] such as [[vinyl chloride]] for [[polyvinyl chloride|PVC]], and [[Methylene diphenyl diisocyanate|MDI]] and [[Toluene diisocyanate|TDI]] for [[polyurethane]]. This is often captive use, consuming locally-produced hydrochloric acid that never actually reaches the open market. Other [[organic chemistry|organic]] compounds produced with hydrochloric acid include [[bisphenol A]] for [[polycarbonate]], [[activated carbon]], and [[ascorbic acid]], as well as numerous [[pharmaceutical]] products.
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| − | ===Other applications===
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| − | Hydrochloric acid is a fundamental chemical, and as such it is used for a large number of small-scale applications, such as [[leather]] processing, household [[cleaning]], and [[building]] [[construction]]. In addition, a way of stimulating [[petroleum#Extraction|oil production]] is by injecting hydrochloric acid into the rock formation of an [[oil well]], dissolving a portion of the rock, and creating a large-pore structure. Oil-well acidizing is a common process in the [[North Sea oil]] production industry.
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| − | Many chemical reactions involving hydrochloric acid are applied in the production of [[food]], food [[ingredients]], and [[food additive]]s. Typical products include [[aspartame]], [[fructose]], [[citric acid]], [[lysine]], hydrolyzed (vegetable) [[protein]] as food enhancer, and in [[gelatin]] production. Food-grade (extra-pure) hydrochloric acid can be applied when needed for the final product.
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| − | ==Physiology and pathology==
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| − | Hydrochloric acid constitutes the majority of [[gastric acid]], the human [[digestive fluid]]. In a complex process and at a large energetic burden, it is secreted by [[parietal cell]]s (also known as oxyntic cells). These cells contain an extensive secretory network (called canaliculi) from which the HCl is secreted into the [[lumen]] of the stomach. They are part of the [[fundic gland]]s (also known as oxyntic glands) in the [[stomach]].
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| − | Safety mechanisms that prevent the damage of the [[epithelium]] of digestive tract by hydrochloric acid are the following:
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| − | * Negative regulators of its release
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| − | * A thick [[mucus]] layer covering the epithelium
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| − | * [[Sodium bicarbonate]] secreted by gastric epithelial cells and pancreas
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| − | * The structure of epithelium ([[tight junction]]s)
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| − | * Adequate blood supply
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| − | * [[Prostaglandin]]s (many different effects: they stimulate mucus and bicarbonate secretion, maintain epithelial barrier integrity, enable adequate blood supply, stimulate the healing of the damaged mucous membrane)
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| − | When, due to different reasons, these mechanisms fail, [[heartburn]] or [[peptic ulcer]]s can develop. Drugs called [[proton pump inhibitor]]s prevent the body from making excess acid in the stomach, while [[antacid]]s neutralize existing acid.
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| − | In some instances, not enough of hydrochloric acid gets produced in the stomach. These pathologic states are denoted by the terms [[hypochlorhydria]] and [[achlorhydria]]. Potentially they can lead to [[gastroenteritis]].
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| − | ==Chemical weapons==
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| − | [[Phosgene]] (COCl<sub>2</sub>) was a common [[chemical warfare]] agent used in [[World War I]]. The main effect of phosgene results from the dissolution of the gas in the mucous membranes deep in the [[lung]], where it is converted by [[hydrolysis]] into [[carbonic acid]] and the corrosive hydrochloric acid. The latter disrupts the [[pulmonary alveolus|alveolar]]-[[capillary]] [[biological membrane|membrane]]s so that the lung becomes filled with fluid ([[pulmonary edema]]).
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| − | Hydrochloric acid is also partly responsible for the harmful or blistering effects of [[mustard gas]]. In the presence of [[water]], such as on the moist surface of the eyes or lungs, mustard gas breaks down to form hydrochloric acid.
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| − | ==Safety==
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| − | {| align="right" border="1" cellspacing="0" cellpadding="3" style="margin: 0 0 0 0.5em; background: #FFFFFF; border-collapse: collapse; border-color: #C0C090;"
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| − | ! {{chembox header}} |[[Dangerous goods]] labels
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| − | |[[Image:Dangclass8.png|150px|Dangerous goods label for hydrochloric acid: corrosive]] [[Image:Hazard C.svg|100px|Dangerous goods label for hydrochloric acid: corrosive]]
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| − | Hydrochloric acid in high concentrations forms acidic mists. Both the mist and the solution have a corrosive effect on human tissue, potentially damaging respiratory organs, eyes, skin and intestines. Upon mixing hydrochloric acid with common oxidizing chemicals, such as [[sodium hypochlorite|bleach (NaClO)]] or [[potassium permanganate|permanganate (KMnO<sub>4</sub>)]], the toxic gas [[chlorine]] is produced. To minimize the risks while working with hydrochloric acid, appropriate precautions should be taken, including wearing rubber or PVC gloves, protective eye goggles, and chemical resistant clothing.
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| − | The hazards of solutions of hydrochloric acid depend on the concentration. The following table lists the [[Directive 67/548/EEC|EU classification]] of hydrochloric acid solutions:
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| − | <!-- EU Index no. 607-002-00-6 —>
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| − | {| align="center" border="1" cellspacing="0" cellpadding="3" style="margin: 0 0 0 0.5em; background: #FFFFFF; border-collapse: collapse; border-color: #C0C090;"
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| − | ! {{chembox header}} colspan="1" | [[Concentration]]<br />by weight
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| − | ! {{chembox header}} colspan="1" | Classification
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| − | ! {{chembox header}} colspan="1" | [[List of R-phrases|R-Phrases]]
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| − | | 10%–25%
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| − | | Irritant ('''Xi''')
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| − | | {{R36/37/38}}
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| − | |-
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| − | | >25%
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| − | | Corrosive ('''C''')
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| − | | {{R34}} {{R37}}
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| − | |-
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| − | |}
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| − | ==See also==
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| − | * [[Acid]]
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| − | * [[Aqua regia]]
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| − | * [[Base (chemistry)]]
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| − | * [[Nitric acid]]
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| − | * [[Sulfuric acid]]
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| − | ==Notes==
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| − | <references />
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| − | ==References==
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| − | * Chang, Raymond. 2006. ''Chemistry,'' 9th ed. New York: McGraw-Hill Science/Engineering/Math. ISBN 0073221031.
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| − | * Cotton, F. Albert, and Geoffrey Wilkinson. 1980. ''Advanced Inorganic Chemistry,'' 4th ed. New York: Wiley. ISBN 0471027758.
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| − | * Guyton, Arthur C., and John E. Hall. 2000. ''Textbook of Medical Physiology''. Philadelphia: Saunders. ISBN 072168677X.
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| − | * Lide, David R., ed. 2005. ''CRC Handbook of Chemistry and Physics,'' 86th ed. Boca Raton: CRC Press. ISBN 0849304865.
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| − | * McMurry, J., and R.C. Fay. 2004. ''Chemistry,'' 4th ed. Upper Saddle River, NJ: Prentice Hall. ISBN 0131402080.
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| − | * Perry, R., D. Green, and J. Maloney. 1984. ''Perry's Chemical Engineers' Handbook,'' 6th ed. New York: McGraw-Hill. ISBN 0070494797.
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| − | ==External links==
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| − | * [http://www.chembuddy.com/?left=CASC&right=density_tables Density table for hydrochloric acid] Retrieved July 24, 2007.
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| − | * [http://webbook.nist.gov/ NIST WebBook, general link] Retrieved July 24, 2007.
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| − | * [http://www.epa.gov/ttn/atw/hlthef/hydrochl.html EPA Hazard Summary] Retrieved July 24, 2007.
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| − | * [http://www.cc.nih.gov/cp/about_lab_med/hcl.html NIH Description and Hazard Summary] Retrieved July 24, 2007.
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| − | * [http://www.americanbio.com/MSDS_PDF/AB00830.pdf Material Safety Data Sheet: Hydrochloric Acid.] ''American Bioanalytical''. Retrieved July 24, 2007.
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| − | * [http://grover.mirc.gatech.edu/data/msds/50.html Hydrochloric acid MSDS.] ''Georgia Institute of Technology''. Retrieved July 24, 2007.
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| − | [[Category:Physical sciences]]
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| − | [[Category:Chemistry]]
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| − | [[Category:Inorganic chemistry]]
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| − | {{credit|139238280}}
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