Hydrogen peroxide

Hydrogen peroxide is a chemical compound. Its molecular formula is H₂O₂. It is used as a cleaner, and as hair bleach. In a concentration of 3% (meaning that there are 3 grams of hydrogen peroxide for 100 grams of a water solution), it can be used to treat wounds. Over time it will slowly become oxygen gas and water through decomposition.

Stuctural formula of hydrogen peroxide. H is hydrogen and O is oxygen. The lines repsent the chemical bonds between the atoms.

A picture to show simply how the atoms may fill space. The white is hydrogen and the red is oxygen.

Chemists often use hydrogen peroxide in chemical reactions. It is a very strong oxidising agent when used with acid and water. Oxidising agents take electrons from other compounds.

2 Fe²⁺(aq) + H₂O₂ + 2 H+(aq) → 2 Fe³⁺(aq) + 2 H₂O(l)

Here hydrogen peroxide takes an electron from the Fe2+ ions and becomes water.

It can also be a reducing agent when used with other compounds. When it acts as a reducing agent, oxygen gas is also produced. Reducing agents give electrons to other compounds. This method is often used to make oxygen in laboratories.

NaOCl + H₂O₂ → O₂ + NaCl + H₂O

Hydrogen peroxide can be bought in shops when mixed with lots of water but is very dangerous when the concentration is higher. It is flammable and causes burns.