Question

The laughing gas is:
(a)- ${{N}_{2}}{{O}_{4}}$
(b)- $NO$
(c)- ${{N}_{2}}O$
(d)- ${{N}_{2}}{{O}_{5}}$

Answer 1

Hint: The laughing gas is an oxide of the element nitrogen. The oxidation number is +1 of nitrogen in laughing gas. It is a neutral and colorless gas.


Complete step by step answer:
The laughing gas is also known as nitrous oxide whose formula is ${{N}_{2}}O$. The other names of laughing gas are Dinitrogen oxide and Nitrogen (I) oxide.
The oxidation number is +1 of nitrogen in laughing gas.
Physically the laughing gas is colorless and neutral, but it has a sweet odor.
Some common preparation methods of the laughing gas or nitrous oxide are:
(i)- By heating ammonium nitrate: When ammonium nitrate is heated at 473-533 K, it forms nitrous oxide and water. The reaction is given below:
$N{{H}_{4}}N{{O}_{3}}\xrightarrow{473-533K}{{N}_{2}}O+2{{H}_{2}}O$
(ii)- Reaction between nitrous acid and Hydroxylamine: When nitrous acid is reacted with Hydroxylamine, it forms nitrous gas and water. The reaction is given below:
$HN{{O}_{2}}+N{{H}_{2}}OH\to {{N}_{2}}O+2{{H}_{2}}O$
(iii)- Reaction between nitrous acid and Hydrazonic acid: When nitrous acid is reacted with Hydrazonic acid, it forms nitrous acid, dinitrogen, and water. The reaction is given below:
$HN{{O}_{2}}+{{N}_{3}}H\to {{N}_{2}}O+{{N}_{2}}+{{H}_{2}}O$
Some chemical reactions of nitrous acid are:
Decomposition of laughing gas forms nitrogen gas and oxygen gas. The reaction is:
$2{{N}_{2}}O\xrightarrow{873K}2{{N}_{2}}(g)+{{O}_{2}}(g)$
When nitrous acid reacts with sodamide at 473 K it forms sodium azide and water. The reaction is given below:
${{N}_{2}}O+NaN{{H}_{2}}\xrightarrow{473K}Na{{N}_{3}}+{{H}_{2}}O$

Therefore the correct answer is an option (c)- ${{N}_{2}}O$.


Note: Nitrous oxide is used as an oxidizer in a rocket motor, due to its less toxicity and stable nature, it is preferred over other oxidizers. It works as an anesthetic and analgesic, so it is used in dentistry.