Anhydrous nitric acid + white phosphorus

Fire shot and the formation of brown fumes

Scientific name: Oxidation of phosphorus with anhydrous nitric acid


Реакция белого фосфора с азотной кислотой (В.В.Загорский)

by Dmitriy Chist


Wear eye protection goggles. NO2 is a poisonous gas! Work in a hood or outdoors.

Always follow general safety recommendations. Please note that conducting chemistry experiments you must comply with the relevant legal procedures in your country.

Reaction formula

Р4 + 20 НNО3 → 4 НРО3 + 20 NО2 + 8 Н2О

Step-by-step instruction

WARNING! This experiment is dangerous! You should NOT perform this at home. ONLY carry out this experiment, if you are a trained chemist, and you understand local safety and legal requirements, which are required to perform such experiments

  1. Preparation of anhydrous nitric acid. Mix 25 ml of concentrated nitric acid and 10 ml of concentrated sulfuric acid in a round bottom flask. Assemble the system for distillation. Distill nitric acid.
  2. Pour a few milliliters of anhydrous nitric acid into a test tube.
  3. Lower the small piece of white phosphorus into the test tube.
  4. Observe the melting of white phosphorus, the releasing of white smoke and the fire shot.

Scientific background

Anhydrous nitric acid is a very strong oxidizing agent and reacts with nonmetals leading to the formation of new acids and nitrogen oxides. Therefore, it easily interacts with white phosphorus. The reaction with white phosphorus occurs very vigorously and is accompanied by an explosion. The formation of metaphosphoric acid instead of orthophosforic acid is explained by the lack of water in the reaction mixture.


Published on 30 June 2015

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst