Question

The reaction of $H_2O_2$ with urea is example for:
A. Substitution
B. Addition
C. Elimination
D. Hydration

Answer 1

Hydrogen peroxide is an oxidizing as well as reducing agent. Hydrogen peroxide mixed with urea is called hyperol. It can be prepared from sodium peroxide. The process is called Merck’s method.

Complete step by step answer:
When urea is {\text{30% }} dissolving in 30% hydrogen peroxide at temperature less than ${\text{6}}{{\text{0}}^{\text{o}}}{\text{C}}$, crystals or platelets of hydrogen peroxide - urea precipitates on cooling.

If it is a substitution reaction then one atom or molecule of urea will be replaced by hydrogen peroxide, but it does not happen when the structure of hyperol is observed.
If it is an elimination reaction, then a molecule of water should be removed, but it also does not happen.
If it is hydration reaction, then a hydroxyl group and proton should be added to urea, but there is no addition of such type
If its addition reaction. Then two or more reactant combine and form new compound without any loss of atoms from the reactant compound, and such type of reaction observed in hyperol as there is no loss of any molecule or atom to form the new product
So, option (B) is correct.

Additional information:
Urea is treated with hydrogen peroxide to form hyperol. The chemical reaction of formation of hyperol is as follows.
${\text{CO(N}}{{\text{H}}_{\text{2}}}{{\text{)}}_{\text{2}}}{\text{ + }}{{\text{H}}_{\text{2}}}{{\text{O}}_{\text{2}}} \to {\text{CO(N}}{{\text{H}}_{\text{2}}}{{\text{)}}_{\text{2}}}{\text{.}}{{\text{H}}_{\text{2}}}{{\text{O}}_{\text{2}}}$

Note: Hydrogen peroxide is prepared from sodium peroxide and action of dilute sulphuric acid but these methods are not produced appreciably. By the action of carbon dioxide on thin paste of ${\text{Ba}}{{\text{O}}_{\text{2}}}$ to produce effective production of hydrogen peroxide.