Question

The number of structural isomers with formula ${C_6}{H_9}N$

Answer 1

Hint:Isomerism is a phenomenon where a compound has the same chemical formula but has different structural formulas and different properties. compounds exhibiting this phenomenon are called isomers. The two main types of isomerism are structural isomerism and stereoisomerism.In more understanding, isomers are compounds which contain exactly the same number of atoms , even though they have the same empirical formula but are different from each other by the way in which atoms are arranged.

Complete answer:
Isomerism is mainly divided into 2 types structural isomerism and stereoisomerism
Chain isomers are isomers when two or more compounds that have the same molecular formula but differ in the branching of carbon atoms.
 Position isomers means when two or more compounds which differ in the position of functional groups or substituent atoms .
 When two or more compounds that have identical molecular formulas but differ in their functional group present is called functional isomers.
Metamerism is exhibited by compounds due to the presence of different alkyl groups on either side of the functional group.
Here we have to find the number of structural isomers available for ${C_6}{H_9}N$
Since the above compound comes under alkyl amine group firstly we can write it in chain structure ,the compound formed is called propylamine.
1.

Here the functional group amine is in the first carbon atom
2.

 When we change the position of functional group amine , we get another isomer
Here amine group is in the second carbon atom.
3.Metamerism is also shown by the compound, here we can insert amine group in main chain

4.tertiary amine group is also possible

So here the total number of structural isomers from ${C_6}{H_9}N$ is 4.

There are 4 structural isomers available for ${C_6}{H_9}N$

Note:
Structural isomers are also known as Constitutional isomers.These isomers have the same empirical formula but their IUPAC names are different , isomerism is a property between a pair (or more) of molecules. Also note that resonance structures are not a type of isomers.