Physical property: The pure HNO3 is a kind of colourless liquid. It has a pungent odor. The density of it about 1.4g/?, the boiling point is 83℃. It is easy to volatilize and dissolve in water with any ratio. The mass fraction of 98% or more of HNO3 is called “Smoke---free nitric acid”. Because this kind of acid is easy to volatilize, it will form white smoke when mixed with humid air and it has causticity.

Chemical property:
(1) It has the quality of acid.
(2) Instability. The appearance of concentrated nitric acid is yellow because it can decomposition NO2 after dissolving. It uaually be stored in brown reagent bottle( to protect light) and be kept in dark cold place.
(3) Strong oxidizing property

Use:  Nitric acid is the important chemical material and the important reagent in laboratory. It can used in industies including making chemical fertilizer, agriacltural chemical, dynamite, dyestuff and salt ect.

Stability and Risk
Risk: It can decomposition and form toxic gas when heated; strong oxidizer, it can sharp reaction or explore with combustible and reducing substances. It has strong acid and can shrp reaction with alkali. It can corrode the most metal(except aluminum and its alloy) and form nitrogen oxide. It can sharp reaction with many common used organics and cause fire and explosion danger.