Question

A tetra-atomic molecule (A) on reaction with nitrogen (l) oxide, produces two substances (B) and (C). (B) is a dehydrating agent while substance (C) is a diatomic gas which shows almost inert behaviour. The substances (A) and (B) and (C) respectively will be:
A.${{\text{P}}_{\text{4}}}{\text{, }}{{\text{P}}_{\text{4}}}{{\text{O}}_{{\text{10}}}}{\text{, }}{{\text{N}}_{\text{2}}}$
B.${{\text{P}}_{\text{4}}}{\text{, }}{{\text{N}}_{\text{2}}}{{\text{O}}_{\text{5}}}{\text{, }}{{\text{N}}_{\text{2}}}$
C.${{\text{P}}_{\text{4}}}{\text{, }}{{\text{P}}_{\text{2}}}{{\text{O}}_{\text{3}}}{\text{, Ar}}$
D.${{\text{P}}_{\text{4}}}{\text{, }}{{\text{P}}_{\text{2}}}{{\text{O}}_{\text{3}}}{\text{, }}{{\text{O}}_{\text{2}}}$ ${P_4}$

Answer 1

When four atoms chemically bond together to form a molecule, then that molecule is known as a tetra atomic molecule. Example: ammonia. Substance which dries or removes water from a material, substance or compound is known as a dehydrating agent. Example: sulfuric acid. When two atoms chemically bond to form a molecule or compound they are known as diatomic molecules. Example: oxygen. Substances which do not react or are unreactive and stable in their naturally occurring form are called as inert substances and they know to show inert behaviour that is they are unreactive. Example: nitrogen.

Complete answer:
Tetra atomic molecule which reacts with nitrogen oxide gives a dehydrating agent, can be tetra phosphorus. Tetra phosphorus with nitrogen oxide gives phosphorus pentoxide that is ${P_4}{O_{10}}$ which is a powerful desiccant and dehydrating agent. Phosphorus pentoxide is a white crystalline solid compound.
The diatomic gas which has inert behaviour is nitrogen that is ${N_2}$.
The reaction that takes place is as follows:
${P_4} + 10{N_2}O \to {P_4}{O_{10}} + {N_2}$
This reaction is a single displacement type of reaction. In this reaction one element of a compound is replaced by another element. The product formed at the end will be more stable than the reactant or the compound before the reaction took place.
It is generally represented by:
$AB + C \to AC + B$
Here, AC will be more stable than AB.
Therefore, the compound (A) is ${P_4}$ that is tetra phosphorous, compound (B) is ${P_4}{O_{10}}$ that is phosphorus pentoxide and compound (C) is ${N_2}$ that is nitrogen gas.

Thus, the correct answer is option A.
Note:
${P_4}{O_{10}}$ is named as phosphorus pentoxide because it is a dimer of ${P_2}{O_5}$.
Uses of phosphorus pentoxide: It is used as a dehydrating agent in reactions. It is used to absorb moisture from substances. Uses of nitrogen: It is used to make fertilizers, nitric acid and explosives.