Question

Decomposition of ${H_2}{O_2}$is prevented by adding:
A. $NaOH$
B. $Mn{O_2}$
C. Acetanilide
D. Carbon powder

Answer 1

Decomposition of hydrogen peroxide can be prevented by adding a negative catalyst which is also known as inhibitors. Negative catalysts are those catalysts which prevent the reaction to happen.

Complete step by step answer:
${H_2}{O_2}$: The chemical name of the compound is hydrogen peroxide. In the structure of hydrogen peroxide one single bond is present between two oxygen atoms. It is an oxidiser as it can release oxygen. So it can be used as an oxidiser.
Catalyst: Those substances which are added in a reaction to affect (either increase or decrease) the rate of reaction. They do not take part in the reaction. They only affect(either increase or decrease) the rate of reaction. The catalysts are divided into two categories:
1. Positive catalyst: The catalysts which on adding increase the rate of reaction, are known as positive catalysts. They generally do not take part in the reaction. They only increase the rate of reaction by increasing the surface area, by making an intermediate, etc.
2. Negative catalyst: The catalysts which on adding decrease the rate of reaction, are known as negative catalysts. They generally do not take part in the reaction. They only decrease the rate of reaction by decreasing the surface area, by making an intermediate, etc.
Factors affecting the rate of reaction:
1. If we increase the concentration of reactants, then the rate of reaction increases.
2. If surface area for the reaction is greater, then the rate of reaction is high.
3. If a positive catalyst is present during the reaction, then rate of reaction increases and if negative catalyst is present during the reaction, then rate of reaction decreases.
Now, according to the question we have to decrease the rate of decomposition of hydrogen peroxide, so we have to add a negative catalyst to it. The negative catalyst for the decomposition of hydrogen peroxide is acetanilide.

So, the correct answer is Option C..

Note:
The negative catalyst for the decomposition of hydrogen peroxide can be alcohol, acetanilide, glycerine, etc. By the addition of any one of these we can decrease the rate of decomposition of hydrogen peroxide.