Is HNO3 a base or acid?

Answer:  HNO₃  is a strong acid, a base, a nitrator, and occasionally a heavy oxidizer. It acts as a base when there is a stronger acid present. Nitric acid is a stronger acid than nitrous acid because the conjugate base is more stable. The excess negative charge of the NO₂  ion is dispersed over two oxygen atoms, whereas the excess negative charge of the NO₃  ion is dispersed over three oxygen atoms.

Water reacts with nitrogen dioxide to produce nitric acid (). Nitric acid is utilised in the production of ammonium nitrate and calcium ammonium nitrate to categorise fertiliser uses. Ammonium nitrate is also utilised in the production of urea ammonium nitrate (UAN), which is used to make explosives as well as fertiliser formulations.