Question

How is decomposition of $H_{2}O_{2}$ accelerated?

Answer 1

i)        Usually peroxy compounds tend to be highly unstable and reactive. Similarly, Hydrogen peroxide is a peroxy compound and also unstable, and it slowly decomposes into water and oxygen. The reaction as follows,  

              $2H_{2} O_{2} =2H_{2}O+O_{2}$

ii)        The decomposition is faster in alkaline medium, and also in the presence of substances like manganese dioxide.  

iii)        It decomposes when sunlight falls on it or when subjected to heat or even exposed to open air.