Application Notes:

Sodium chloride, also known as common salt, table salt, or halite is the

salt most responsible for the salinity of the ocean and is present in the

extracellular fluid of many multicellular organisms. 

Sodium chloride is used in many applications, from manufacturing pulp

and paper to setting dyes in textiles and fabric, to producing soaps and

detergents.  It is often used to suppress the freezing point of water with a

melting ability down to temperatures of -15°C (5°F).

Sodium chloride is sometimes used as a cheap and safe desiccant due to

its hygroscopic properties, making salting an effective method of food

preservation historically.  Even though more effective desiccants are

available, few are safe for humans to ingest.

Sodium chloride is also the raw material used to produce chlorine which

itself is required for the production of many modern materials ranging

from polyvinyl chloride (PVC) to pesticides.  Industrially, elemental

chlorine is usually produced by the electrolysis of sodium chloride dissolved

in water.  

Sodium metal is produced commercially through the electrolysis of liquid

sodium chloride.  This is done in a “Down’s cell” in which sodium chloride

is mixed with calcium chloride to lower the melting point below 700 °C.  

Sodium chloride is used in other chemical processes for the large-scale

production of compounds containing sodium or chlorine. In the “Solvay process,”

sodium chloride is used for producing sodium carbonate and calcium chloride.

In the “Mannheim process” and in the “Hargreaves process.” It is used for the

production of sodium sulfate and hydrochloric acid.