Sodium nitrite (NaNO₂) is an inorganic salt formed by the combination of nitrite ion and sodium ion. Sodium nitrite is easy to deliquesce and soluble in water and liquid ammonia. Its aqueous solution is alkaline and its pH is about 9. It is slightly soluble in organic solvents such as ethanol, methanol and ether. Sodium nitrite has a salty taste and is used to make fake table salt. Sodium nitrite will react with oxygen to form sodium nitrate when exposed to air. If heated above 320°C, it will decompose to produce oxygen, nitrogen oxide and sodium oxide. Contact with organic matter is easy to burn and explode. Because of its salty taste and low price, it is often used as an unreasonable substitute for table salt when making illegal food. Because sodium nitrite is toxic, food containing industrial salt is very harmful to humans and carcinogenic.

Physical and chemical properties

white or slightly yellow crystals, specific gravity 2.168 (at 20°C), easily soluble in water, liquid ammonia, slightly soluble in methanol, ethanol, ethyl ether, and highly hygroscopic.

Purpose

Mainly used for manufacturing nitro compounds, azo dyes, mordants for fabric dyeing, bleaching agents, metal heat treatment agents and the pharmaceutical industry