Chloride

The term chloride refers to a compound or molecule that contains either a chlorine anion (Cl−
), which is a negatively charged chlorine atom, or a non-charged chlorine atom covalently bonded to the rest of the molecule by a single bond (–Cl). The pronunciation of the word "chloride" is /ˈklɔːraɪd/.[1]

Chloride salts such as sodium chloride are often soluble in water.[2] It is an essential electrolyte located in all body fluids responsible for maintaining acid/base balance, transmitting nerve impulses and regulating liquid flow in and out of cells. Other examples of ionic chlorides include potassium chloride (KCl), calcium chloride (CaCl
2), and ammonium chloride (NH
4Cl). Examples of covalent chlorides include methyl chloride (CH
3Cl), carbon tetrachloride (CCl
4), sulfuryl chloride (SO
2Cl
2), and monochloramine (NH
2Cl).

## Contents

* 1 Electronic properties
* 2 Reactions of chloride
* 3 Other oxyanions
* 4 Occurrence in nature
* 4.1 Role in biology
* 4.2 Corrosion
* 4.3 Environmental threats
* 5 Production
* 6 Examples and uses
* 6.1 Water quality and processing
* 6.2 Food
* 7 See also
* 8 References

## Electronic properties

A chloride ion (diameter 181 pm) is much larger than a chlorine atom (diameter 99 pm). The chlorine atom's hold on the valence shell is weaker because the chloride anion has one more electron than it does.[3] The ion is colorless and diamagnetic. In aqueous solution, it is highly soluble in most cases; however, for some chloride salts, such as silver chloride, lead(II) chloride, and mercury(I) chloride, they are only slightly soluble in water.[4] In aqueous solution, chloride is bonded by the protic end of the water molecules.

## Reactions of chloride

Chloride can be oxidized but not reduced. The first oxidation, as employed in the chlor-alkali process, is conversion to chlorine gas. Chlorine can be further oxidized to other oxides and oxyanions including hypochlorite (ClO−, the active ingredient in chlorine bleach), chlorine dioxide (ClO2), chlorate (ClO−3), and perchlorate (ClO−4).

In terms of its acid–base properties, chloride is a weak base as indicated by the negative value of the pKa of hydrochloric acid. Chloride can be protonated by strong acids, such as sulfuric acid:

NaCl + H2SO4 → NaHSO4 \+ HCl

Ionic chloride salts react with other salts to exchange anions. The presence of halide ions like chloride can be detected using silver nitrate. A solution containing chloride ions will produce a white silver chloride precipitate:[5]

Cl− \+ Ag+ → AgCl

The concentration of chloride in an assay can be determined using a chloridometer, which detects silver ions once all chloride in the assay has precipitated via this reaction.

Chlorided silver electrodes are commonly used in ex vivo electrophysiology.[6]

## Other oxyanions

Chlorine can assume oxidation states of −1, +1, +3, +5, or +7. Several neutral chlorine oxides are also known.

Chlorine oxidation state  | −1  | +1  | +3  | +5  | +7

|
|
|
|
|

Name  | chloride | hypochlorite | chlorite | chlorate | perchlorate
Formula  | Cl− | ClO− | ClO−2 | ClO−3 | ClO−4
Structure  |  |  |  |  |

## Occurrence in nature

In nature, chloride is found primarily in seawater, which has a chloride ion concentration of 19400 mg/liter.[7] Smaller quantities, though at higher concentrations, occur in certain inland seas and in subterranean brine wells, such as the Great Salt Lake in Utah and the Dead Sea in Israel.[8] Most chloride salts are soluble in water, thus, chloride-containing minerals are usually only found in abundance in dry climates or deep underground. Some chloride-containing minerals include halite (sodium chloride NaCl), sylvite (potassium chloride KCl), bischofite (MgCl2∙6H2O), carnallite (KCl∙MgCl2∙6H2O), and kainite (KCl∙MgSO4∙3H2O). It is also found in evaporite minerals such as chlorapatite and sodalite.

### Role in biology

Chloride has a major physiological significance,[9] which includes regulation of osmotic pressure, electrolyte balance and acid-base homeostasis. Chloride is present in all body fluids,[10] and is the most abundant extracellular anion which accounts for around one third of extracellular fluid's tonicity.[11][12]

Chloride is an essential electrolyte, playing a key role in maintaining cell homeostasis and transmitting action potentials in neurons.[13] It can flow through chloride channels (including the GABAA receptor) and is transported by KCC2 and NKCC2 transporters.

Chloride is usually (though not always) at a higher extracellular concentration, causing it to have a negative reversal potential (around −61 mV at 37 °C in a mammalian cell).[14] Characteristic concentrations of chloride in model organisms are: in both E. coli and budding yeast are 10–200 mM (dependent on medium), in mammalian cells 5–100 mM and in blood plasma 100 mM.[15]

Chloride is also needed for the production of hydrochloric acid in the stomach.[16]

The concentration of chloride in the blood is called serum chloride, and this concentration is regulated by the kidneys. A chloride ion is a structural component of some proteins; for example, it is present in the amylase enzyme. For these roles, chloride is one of the essential dietary minerals (listed by its element name chlorine). Serum chloride levels are mainly regulated by the kidneys through a variety of transporters that are present along the nephron.[17] Most of the chloride, which is filtered by the glomerulus, is reabsorbed by both proximal and distal tubules (majorly by proximal tubule) by both active and passive transport.[18]

### Corrosion

The structure of sodium chloride, revealing the tendency of chloride ions (green spheres) to link to several cations.

The presence of chlorides, such as in seawater, significantly worsens the conditions for pitting corrosion of most metals (including stainless steels, aluminum and high-alloyed materials). Chloride-induced corrosion of steel in concrete leads to a local breakdown of the protective oxide form in alkaline concrete, so that a subsequent localized corrosion attack takes place.[19]

### Environmental threats

Increased concentrations of chloride can cause a number of ecological effects in both aquatic and terrestrial environments. It may contribute to the acidification of streams, mobilize radioactive soil metals by ion exchange, affect the mortality and reproduction of aquatic plants and animals, promote the invasion of saltwater organisms into previously freshwater environments, and interfere with the natural mixing of lakes. Sodium chloride has been shown to change the composition of microbial species at relatively low concentrations, hinder the denitrification process, a microbial process essential to nitrate removal and the conservation of water quality, and inhibit the nitrification and respiration of organic matter.[20]

## Production

The chlor-alkali industry is a major consumer of the world's energy budget. This process converts concentrated sodium chloride solutions into chlorine and sodium hydroxide, which are used to make many other materials and chemicals. The process involves two parallel reactions:

2 Cl− → Cl2 \+ 2 e−
2 H2O \+ 2 e− → H2 \+ 2 OH−
Basic membrane cell used in the electrolysis of brine. At the anode (A), chloride (Cl−) is oxidized to chlorine. The ion-selective membrane (B) allows the counterion Na+ to freely flow across, but prevents anions such as hydroxide (OH−) and chloride from diffusing across. At the cathode (C), water is reduced to hydroxide and hydrogen gas.

## Examples and uses

An example is table salt, which is sodium chloride with the chemical formula NaCl. In water, it dissociates into Na+ and Cl− ions. Salts such as calcium chloride, magnesium chloride, potassium chloride have varied uses ranging from medical treatments to cement formation.[2]

Calcium chloride (CaCl2) is a salt that is marketed in pellet form for removing dampness from rooms and lawn care. Calcium chloride is also used for maintaining unpaved roads and for fortifying roadbases for new construction. In addition, calcium chloride is widely used as a de-icer, since it is effective in lowering the melting point when applied to ice.[21]

Examples of covalently-bonded chlorides are phosphorus trichloride, phosphorus pentachloride, and thionyl chloride, all three of which are reactive chlorinating reagents.

### Water quality and processing

Chloride is also a useful and reliable chemical indicator of river and groundwater fecal contamination, as chloride is a non-reactive solute and ubiquitous to sewage and potable water. Many water regulating companies around the world utilize chloride to check the contamination levels of the rivers and potable water sources.[22]

### Food

Chloride salts such as sodium chloride are used to preserve food and as nutrients or condiments.

## See also

* Halide
* Renal chloride reabsorption

## References

1. ↑ Wells, John C. (2008), Longman Pronunciation Dictionary (3rd ed.), Longman, p. 143, ISBN 9781405881180
2. ↑ 2.0 2.1 Green, John, and Sadru Damji. "Chapter 3." Chemistry. Camberwell, Vic.: IBID, 2001. Print.
3. ↑ "Size of Atoms". http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch7/size.html.
4. ↑ Zumdahl, Steven (2013). Chemical Principles (7th ed.). Cengage Learning. pp. 109. ISBN 978-1-285-13370-6.
5. ↑ "Testing for halide ions - Group 0 and testing ions - GCSE Chemistry (Single Science) Revision - WJEC" (in en-GB). https://www.bbc.co.uk/bitesize/guides/zm426yc/revision/2.
6. ↑ Molleman, Areles (2003). "Patch Clamping: An Introductory Guide to Patch Clamp Electrophysiology". Wiley & Sons. ISBN 978-0-471-48685-5.
7. ↑ "Chloride and Salinity". 8 September 2011. https://www.ldeo.columbia.edu/edu/k12/snapshotday/activities/2011/Classroom HS activity/chloride conversion/Chloride and Salinity.pdf.
8. ↑ Greenwood, N. N. (1984). Chemistry of the elements (1st ed.). Oxford [Oxfordshire]: Pergamon Press. ISBN 9780750628327.
9. ↑ Raut, Satish (2024). "Chloride ions in health and disease" (in en). Bioscience Reports 44 (5). doi:10.1042/BSR20240029. PMID 38573803.
10. ↑ Deane, Norman; Ziff, Morris; Smith, Homer W. (1952). "The distribution of total body chloride in man" (in en). Journal of Clinical Investigation 31 (2): p. 201, Table 1. doi:10.1172/JCI102592. PMID 14907900.
11. ↑ Berend, Kenrick; van Hulsteijn, Leonard Hendrik; Gans, Rijk O.B. (April 2012). "Chloride: The queen of electrolytes?". European Journal of Internal Medicine 23 (3): 203–211. doi:10.1016/j.ejim.2011.11.013. PMID 22385875.
12. ↑ Rein, Joshua L.; Coca, Steven G. (1 March 2019). ""I don't get no respect": the role of chloride in acute kidney injury". American Journal of Physiology. Renal Physiology 316 (3): F587–F605. doi:10.1152/ajprenal.00130.2018. ISSN 1931-857X. PMID 30539650.
13. ↑ Jentsch, Thomas J.; Stein, Valentin; Weinreich, Frank; Zdebik, Anselm A. (2002-04-01). "Molecular Structure and Physiological Function of Chloride Channels". Physiological Reviews 82 (2): 503–568. doi:10.1152/physrev.00029.2001. ISSN 0031-9333. PMID 11917096. http://physrev.physiology.org/content/82/2/503.
14. ↑ "Equilibrium potentials". http://www.d.umn.edu/~jfitzake/Lectures/DMED/IonChannelPhysiology/MembranePotentials/EquilibriumPotentials.html.
15. ↑ Milo, Ron; Philips, Rob. "Cell Biology by the Numbers: What are the concentrations of different ions in cells?". http://book.bionumbers.org/what-are-the-concentrations-of-different-ions-in-cells/.
16. ↑ "Blood (Serum) Chloride Level Test". http://www.med.umich.edu/1libr/aha/aha_schlorid_crs.htm.
17. ↑ Nagami, Glenn T. (1 July 2016). "Hyperchloremia – Why and how" (in en). Nefrología (English Edition) 36 (4): 347–353. doi:10.1016/j.nefro.2016.04.001. ISSN 2013-2514. PMID 27267918. https://www.revistanefrologia.com/en-hyperchloremia-why-how-articulo-S021169951630025X.
18. ↑ Shrimanker, Isha; Bhattarai, Sandeep (2020). Electrolytes. StatPearls Publishing. PMID 31082167.
19. ↑ Criado, M. (January 2015). "13. The corrosion behaviour of reinforced steel embedded in alkali-activated mortar" (in en). Handbook of Alkali-Activated Cements, Mortars and Concretes. Woodhead Publishing. pp. 333–372. doi:10.1533/9781782422884.3.333. ISBN 978-1-78242-276-1. https://www.sciencedirect.com/science/article/pii/B9781782422761500137.
20. ↑ Kaushal, S. S. (19 March 2009). "Chloride" (in en). Encyclopedia of Inland Waters. Academic Press. pp. 23–29. ISBN 978-0-12-370626-3.
21. ↑ "Common Salts". Georgia State University. http://hyperphysics.phy-astr.gsu.edu/hbase/Chemical/saltcom.html.
22. ↑ "Chlorides". http://www.gopetsamerica.com/substance/chlorides.aspx.

* v
* t
* e

Salts and covalent derivatives of the chloride ion

HCl |  |  |  | He

|
|
|
|

LiCl | BeCl2 | BCl3
B2Cl4 | CCl4 | NCl3
ClN3 | Cl2O
ClO2
Cl2O7 | ClF
ClF3
ClF5 | Ne
NaCl | MgCl2 | AlCl
AlCl3 | SiCl4 | P2Cl4
PCl3
PCl5 | S2Cl2
SCl2
SCl4 | Cl2 | Ar
KCl | CaCl
CaCl2 | ScCl3 | TiCl2
TiCl3
TiCl4 | VCl2
VCl3
VCl4
VCl5 | CrCl2
CrCl3
CrCl4 | MnCl2 | FeCl2
FeCl3 | CoCl2
CoCl3 | NiCl2 | CuCl
CuCl2 | ZnCl2 | GaCl2
GaCl3 | GeCl2
GeCl4 | AsCl3
AsCl5 | Se2Cl2
SeCl4 | BrCl | KrCl
RbCl | SrCl2 | YCl3 | ZrCl3
ZrCl4 | NbCl4
NbCl5 | MoCl2
MoCl3
MoCl4
MoCl5
MoCl6 | TcCl4 | RuCl3 | RhCl3 | PdCl2 | AgCl | CdCl2 | InCl
InCl2
InCl3 | SnCl2
SnCl4 | SbCl3
SbCl5 | Te3Cl2
TeCl4 | ICl
ICl3 | XeCl
XeCl2
CsCl | BaCl2 |  | HfCl4 | TaCl5 | WCl2
WCl3
WCl4
WCl5
WCl6 | Re3Cl9
ReCl4
ReCl5
ReCl6 | OsCl4 | IrCl2
IrCl3
IrCl4 | PtCl2
PtCl4 | AuCl
AuCl3 | Hg2Cl2,
HgCl2 | TlCl | PbCl2,
PbCl4 | BiCl3 | PoCl2,
PoCl4 | AtCl  | RnCl2
FrCl | RaCl2 |  | Rf  | Db  | Sg  | Bh  | Hs  | Mt  | Ds  | Rg  | Cn  | Nh  | Fl  | Mc  | Lv  | Ts  | Og
| ↓  |  |
LaCl3 | CeCl3 | PrCl3 | NdCl2,
NdCl3 | PmCl3 | SmCl2,
SmCl3 | EuCl2,
EuCl3 | GdCl3 | TbCl3 | DyCl2,
DyCl3 | HoCl3 | ErCl3 | TmCl2
TmCl3 | YbCl2
YbCl3 | LuCl3
AcCl3 | ThCl4 | PaCl5 | UCl3
UCl4
UCl5
UCl6 | NpCl4 | PuCl3 | AmCl2
AmCl3 | CmCl3 | BkCl3 | CfCl3 | EsCl3 | Fm  | Md  | No  | LrCl3

Template:Monatomic anion compounds

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Chloride. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Chemistry:Chloride&oldid=4178700"
*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template