Red phosphorus and bromine

Two substances react with an intense flame

Scientific name: Exothermic interaction of red phosphorus with bromine


Red phosphorus and bromine

by ChemToddler

Red Phosphorus and Bromine

Red Phosphorus and Bromine

by FaceOfChemistry

reaction between red phosphorus and bromine vapor_2P + 5Br2 → 2PBr5


Wear eye protection goggles. Use gloves. Bromine forms a poisonous vapour! Perform the reaction 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

2 P + 3 Br2 → 2 PBr3

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. Put 1.2 g of red phosphorus in a porcelain cup.
  2. Take 3 ml of bromine using a measuring tube.
  3. Pour the bromine into the porcelain cup containing red phosphorus.
  4. Observe the intense burning.

Scientific background

As a halogen bromine is a strong oxidant. This property of bromine is due to its position in the periodic table, high electronegativity, the lack of a single electron to fill the outer electron level and the low energy Br-Br bonds. Red phosphorus is a nonmetal that has reducing properties. Phosphorus is oxidized to phosphorus bromide, which forms the smoke. A large amount of heat is released which provides the ignition.


Published on 15 May 2015

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