What does hydrogen peroxide spontaneously decompose into?

Hydrogen peroxide spontaneously decomposes into water and oxygen.

The equation for the reaction is

##"2H"_2"O"_2 → "2H"_2"O" + "O"_2##

The rate of decomposition is slow at room temperature, but it increases with temperature.

The rate increases rapidly in the presence of catalysts such as ##"MnO"_2## and ##"KI"##.

Hydrogen peroxide is a powerful oxidizing agent. At low concentrations (3 %), it is used as a disinfectant and a bleach.

The UV light from the sun catalyzes the reaction.

If you leave hydrogen peroxide in a clear container in sunlight, it decomposes much faster.

That's why it's sold to the public in brown bottles.

At concentrations of 70 to 98+ %, it is used as an oxidizer for rocket fuel.