Sodium Chloride
Definition and meaning of Sodium Chloride in chemistry.
Sodium chloride is a common ionic compound with the chemical formula NaCl. It consists of a perfectly even ratio of positively charged sodium ions and negative chloride ions. This chemical is the specific salt most responsible for the high salinity of ocean seawater.
In more detail
In its solid state, sodium chloride forms a massive ionic crystalline lattice. Each sodium ion (Na+) is tightly surrounded by exactly six chloride ions (Cl-). Each chloride ion is also surrounded by six sodium ions in a face-centered cubic arrangement.
This strong electrostatic attraction between oppositely charged ions gives the compound a high melting point. This strong ionic attraction also makes the solid salt crystals highly brittle and easy to shatter. Sodium chloride dissolves very easily in polar liquid solvents like plain water.
The rigid crystal lattice breaks apart entirely when the salt dissolves in the water. These free-moving ions allow the salty water solution to easily conduct electrical currents. Companies produce sodium chloride on a massive scale by evaporating ocean seawater or mineral brine.
Miners also extract the compound directly from the earth by mining solid halite rock salt. Industrially, this salt acts as the primary source for producing pure sodium and chlorine compounds. Factories use it in the chlor-alkali process to manufacture chlorine gas and sodium hydroxide.
In biology, sodium chloride is absolutely critical for maintaining proper fluid balance in animal bodies. It also helps transmit electrical nerve impulses and controls routine muscle contractions in animals.
Key facts
| Formula | NaCl |
|---|---|
| Molar mass | 58.44 g/mol |
| Crystal structure | Face-centered cubic |
| Melting point | 801 °C |
| Common name | Table salt |
During cold winters, city workers frequently spread thick rock salt onto frozen, icy roads. The dissolved sodium chloride chemically lowers the natural freezing point of the liquid water. This reaction melts the dangerous ice in a chemical process called freezing-point depression.
Frequently asked questions
Why does solid sodium chloride fail to conduct electricity?
The ions are locked tightly into a rigid crystalline lattice and cannot move. It only conducts electricity when melted or dissolved in water, which frees the ions.
How does salt preserve food?
Salt draws liquid water out of microbial cells through a process called osmosis. This dehydrates the bacteria and fungi that cause food spoilage, stopping their growth.
Related terms
Sources & references
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