has role nitrate nitrogen oxoacid reagent nitric acid A nitrogen oxoacid of formula HNO3 in which the nitrogen atom is bonded to a hydroxy group and by equivalent bonds to the remaining two oxygen atoms. HNO3 HONO2 Nitric acid Salpetersaeure [NO2(OH)] acide azotique acide nitrique azotic acid hydrogen nitrate hydrogen trioxonitrate(1-) hydroxidodioxidonitrogen trioxonitric acid protic solvent