Peroxynitric acid

Peroxynitric acid or peroxonitric acid is a chemical compound with the formula HNO
₄. It is an oxyacid of nitrogen, after peroxynitrous acid.

Peroxynitric acid

Names
Preferred IUPAC name Hydroxy nitrate
Systematic IUPAC name Hydroxy nitrate[1][2][3]
Identifiers
CAS Number	26404-66-0 N
3D model (JSmol)	Interactive image
ChemSpider	58833 Y
PubChem CID	65357
CompTox Dashboard (EPA)	DTXSID201030501
InChI Key: UUZZMWZGAZGXSF-UHFFFAOYSA-N Y[Pubchem]
SMILES [N+](=O)([O-])OO
Properties
Chemical formula	HNO4
Molar mass	79.01224 g/mol
Conjugate base	Peroxynitrate
Related compounds
Related compounds	Peroxynitrous acid Peroxynitrate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Preparation

Peroxynitrate, the conjugate base of peroxynitric acid, is formed rapidly during decomposition of peroxynitrite in neutral conditions.^[4]

Atmospheric chemistry

Peroxynitric acid is formed in the atmosphere, although it is unstable, it is important as a reservoir for NO₂ through the reversible radical reaction:^[5]

HO
₂NO
₂ ⇌ HO^•
₂ + NO^•
₂