Question

Decomposition of ${H_2}{O_2}$ can be prevented by addition of:
A. Acetanilide
B. Benzene
C. Alkali metal oxide
D. $Mn{O_2}$

Answer 1

Hint: Try to recall that there are several negative catalysts which can be used to prevent the decomposition of ${H_2}{O_2}$ and they act as stabilizer to ${H_2}{O_2}$.

Complete step by step solution:
1. It is known that; hydrogen peroxide is unstable and will decompose. The molecular formula of hydrogen peroxide is ${H_2}{O_2}$.
2. It is seen that over time it will decompose into water and oxygen. The reaction is:
$2{H_2}{O_2} \to 2{H_2}O + {O_2}$.
3. It has been seen that ${H_2}{O_2}$ decomposes when exposed to heat and light. That is why it is kept in dark colour bottles and suggested that to be kept in a cool place.
4. Also, we know that ${H_2}{O_2}$ is an oxidizing agent and it oxidizes things by releasing an oxygen atom as a free radical.
5. The decomposition of hydrogen peroxide using manganese dioxide ($Mn{O_2}$) as a catalyst is extremely fast and exothermic.
6. Also, ${H_2}{O_2}$ will decompose when exposed to various catalysts like metal ions, metallic particles etc.
7. Hydrogen peroxide cannot be stored in glass bottles, since the rough surface of glass contains alkali metal oxides and hydrogen peroxide reacts with alkali metal oxides.
8. It is also seen that substances like Urea, Sodium Stannate, Acetanilide, phosphoric acid, glycerine etc. act as negative catalysts in the decomposition of hydrogen peroxide.
9. When benzene is added to ${H_2}{O_2}$, then benzene gets converted into phenol.

Therefore, from above points it can be concluded that option A is the correct option.

Note: It should be remembered that ${H_2}{O_2}$ will break down on exposure to UV light.
Due to its oxidizing nature, it is also used as a bleaching agent.You may also notice physicians use hydrogen peroxide as antiseptic.