nitric

Nitric is an adjective used in chemistry to refer to compounds containing nitrogen in combination with oxygen, or to processes and species derived from nitric acid. The most common reference is to nitric acid, HNO3, a strong mineral acid.

Nitric acid is a colorless to yellowish, highly corrosive liquid and a powerful oxidizing agent. It is used widely in chemical manufacturing, metal processing, and the production of fertilizers and explosives. Industrial production proceeds mainly via the Ostwald process, which oxidizes ammonia to nitrogen monoxide and nitrogen dioxide, which are absorbed in water to yield nitric acid.

Derivatives of nitric acid include nitrates and nitrites, which are salts formed from HNO3 and are important as fertilizers, preservatives, and in various industrial applications. Nitric acid also yields nitric oxide (NO), a diatomic gas that serves as a biological signaling molecule and regulates vascular tone in animals. Nitro compounds and nitrate esters are a broad class of organonitrogen compounds used in pharmaceuticals, dyes, explosives, and propellants; nitrate groups are introduced by nitration reactions.

In the environment, nitrogen oxides (NO and NO2) are air pollutants formed from combustion and participate in atmospheric chemistry that can lead to acid rain and photochemical smog. Nitric acid contributes to acid deposition, and nitrates can accumulate in soil and water.

Safety: nitric acid is highly corrosive and emits fumes; handling requires adequate ventilation, compatible materials, and protective equipment.

Nitric as a term thus encompasses a range of nitrogen-oxygen chemistry, from acids and gases to salts and organic derivatives.