sodium chloride

sodium chloride
Didier Descouens · CC BY-SA 4.0 · source
Name	Sodium chloride
Formula	NaCl
Molar mass	58.44 g·mol−1
Density	2.165 g·cm−3
Melting point	801 °C
Boiling point	1413 °C
Appearance	white crystalline solid

sodium chloride Sodium chloride is an inorganic ionic compound composed of sodium and chlorine that forms colorless cubic crystals and is the principal constituent of common salt. It plays central roles in disciplines ranging from chemistry and periodic table studies to applications in industry and international trade. Its ubiquity links it to historical events such as the Salt March and institutions including the British East India Company and the International Maritime Organization.

Properties

Sodium chloride crystallizes in the rock salt structure studied by Linus Pauling, John Desmond Bernal, and William Henry Bragg, and displays a cubic lattice with each ion coordinated to six counterions as described in work by Max von Laue and Arthur Compton. Its high lattice energy and ionic bonding parameters are subjects in textbooks by Gilbert N. Lewis and Walther Nernst, and influence macroscopic properties measured in standards from National Institute of Standards and Technology and International Union of Pure and Applied Chemistry. Optical and electrical characteristics are referenced in apparatus developed at CERN and measured in experiments linked to Ernest Rutherford-era scattering, while thermodynamic data inform models used by researchers at Massachusetts Institute of Technology and California Institute of Technology.

Occurrence and production

Naturally occurring deposits of the compound are found in evaporite formations documented by geologists from Royal Society expeditions and mining operations operated historically by the Salt Union and modern companies such as Cargill. It is abundant in seawater studied by oceanographers at institutions like Scripps Institution of Oceanography and sampled during voyages of HMS Beagle and Endeavour (ship). Industrial production methods such as vacuum evaporation and solution mining are technologies developed and refined by engineers associated with Kellogg Company-era processes and equipment vendors like KBR, Inc., while modern brine extraction is regulated by agencies including the Environmental Protection Agency and trade overseen by the World Trade Organization.

Uses

As a preservative and seasoning it has been integral to culinary traditions recorded by chefs associated with institutions like Le Cordon Bleu and markets such as Billingsgate Market and Pike Place Market. In chemical manufacture it is a feedstock for chloralkali plants pioneered by inventors linked to Humphry Davy and firms such as Dow Chemical Company and Solvay S.A.. Deicing operations on infrastructure designed by municipal engineers referencing standards from American Society of Civil Engineers and Transport for London use large quantities, while water treatment and textile processes rely on practices codified by organizations such as World Health Organization and International Organization for Standardization.

Health and safety

Dietary intake guidelines produced by World Health Organization and United States Department of Agriculture address risks related to excessive consumption noted in studies from Harvard T.H. Chan School of Public Health and public health bodies in National Health Service (England). Occupational exposure limits set by agencies like Occupational Safety and Health Administration and European Chemicals Agency govern handling in facilities operated by corporations such as BASF and Evonik Industries. Toxicological profiles investigated in research published by authors affiliated with Johns Hopkins University and Mayo Clinic detail effects on blood pressure and renal function with references to clinical trials registered at National Institutes of Health.

History

The cultural and economic importance is reflected in archaeological finds from sites associated with Ancient Egypt, Roman Empire, and Han dynasty economies, and in trade routes chronicled alongside the Silk Road and the operations of the Venetian Republic. Historic policies and events such as the Salt March and the Salt Tax debates involved figures like Mahatma Gandhi and institutions including the British Raj and Ottoman Empire. Technological developments in extraction and refinement are linked to innovators and companies from the eras of Industrial Revolution entrepreneurs to 20th-century industrialists tied to Standard Oil-era infrastructures.

Chemistry and reactions

Reactivity with water, acids, and bases is covered in treatises by Svante Arrhenius and Jöns Jakob Berzelius, while electrolysis of brine yielding chlorine and sodium hydroxide follows principles explored by Michael Faraday and implemented in cells developed by engineers at Thames Ironworks-era firms and modern manufacturers like Ineos. Solubility and colligative properties were subjects in studies by Jacobus Henricus van 't Hoff and figure in cryoscopic and osmotic work conducted at laboratories in University of Cambridge and University of Oxford. Complexation and ion-pair behavior inform modern computational chemistry approaches used by research groups at ETH Zurich and École Normale Supérieure.

Category:Chemical compounds