Decomposition of ${H_2}{O_2}$ is prevented in presence of
(A) Acetanilide
(B) Glycol
(C) Oxygen
(D) none of the above

Hint: To solve this problem, firstly we have to understand the concept behind the decomposition of Hydrogen Peroxide $({H_2}{O_2})$, why and how does it take place and the role of catalysts involved and then we will be finding the ways and catalyst used to prevent this decomposition and hence we will approach our answer.

Complete step by step solution:
> Decomposition: Decomposition is also called chemical breakdown, in this process or effect of simplifying a single chemical entity into two or more fragments. The chemical reaction involving the formation of two or more products from a single entity is called a decomposition reaction.
> Hydrogen peroxide easily breaks down (decompose) into water and oxygen. It is an exothermic reaction which can take place naturally (slowly) and water and oxygen gas formed. Also, there are several catalysts which are used to speed up this reaction. For example, potassium iodide, manganese (IV) oxide, etc.
> The generalized reaction for chemical decomposition in the breakdown of a hydrogen peroxide compound is:
$2{H_2}{O_2} \to 2{H_2}O + {O_2}$
 > Now, when we talk about the prevention of this process, there are various catalysts which are used to prevent the decomposition reaction of hydrogen peroxide. for example, Acetanilide, glycerol and phosphoric acid.
Hence, the solution to this question is A – Acetanilide.

> Decomposition of ${H_2}{O_2}$ is interfered in the presence of acetanilide. Acetanilide acts as a stabilizer which when added to the solutions decelerates the decomposition.
 > Acetanilide is an odorless solid having a flake-like appearance; it was formerly known by the trade name Antifebrin. It possesses analgesic as well as antipyretic activity.

Note: Acetanilide is used to stabilize cellulose ester varnishes as an inhibitor of hydrogen peroxide decomposition and It has also found uses in the intermediation in rubber accelerator, dyes and in camphor synthesis. It was the first aniline derivative found to have analgesic as well as antipyretic properties.