Overview

Nitric acid (NYE-trik AS-id) is a colorless to yellowish liquid with a distinctive acrid (biting), suffocating, or choking odor. The acid tends to decompose when exposed to light, producing nitrogen dioxide (NO₂), itself a brownish gas. The yellowish tinge often observed in nitric acid is caused by the presence of small amounts of the nitrogen dioxide. Nitric acid is one of the strongest oxidizing agents known and attacks almost all metals with the notable exceptions of gold and platinum.

Key Facts

Other Names:

Aqua fortis; engraver's acid; azotic acid

Formula:

HNO₃

Elements:

Hydrogen, nitrogen, oxygen

Compound Type:

Inorganic acid

State:

Liquid

Molecular Weight:

63.01 g/mol

Melting Point:

−41.6°C (−42.9°F)

Boiling Point:

83°C (180°F); decomposes

Solubility:

Miscible with water; decomposes in ethyl alcohol; reacts violently with most organic solvents

Nitric acid has been known to scholars for many centuries. Probably the earliest description of its synthesis...