Question

How many structural isomers of ${C_5}{H_{10}}O$ are there?

Answer 1

Hint:Isomers are molecules which have the same molecular formula that is the same number of atoms of each element but different arrangements of atoms in space or have different molecular structure. Isomers also have different physical and chemical properties.

Complete step by step answer:
-Chemical formula of the given compound is ${C_5}{H_{10}}O$.
-This chemical compound is similar to aldehydes and ketones. Then all isomers of the given compound are either aldehyde or ketones. Also, we know that oxygen formed a double bond with a carbon atom. Isomers of ${C_5}{H_{10}}O$ are shown in the figure below:

As shown in the above figure aldehydes and are formed with the same molecular formula and all compounds are isomers of each other. Also, the number of atoms of each element is the same in all compounds shown in the figure but there is a different molecular structure for each compound.
There are four aldehydes and three ketones exist with the chemical formula ${C_5}{H_{10}}O$.
Then, there are seven structural isomers of ${C_5}{H_{10}}O$.
Hence the correct answer is option D.

Note:
Isomers have the same chemical formula but have different physical and chemical properties. Melting and boiling point of two isomers are different and there is a large difference. Isomers also show different chemical behavior to different chemicals. Functional groups may be different in isomers, as we see in the above solution aldehydes and ketones are isomers of each other.