Question

Total number of metamers represented by the formula ${{C}_{4}}{{H}_{10}}O$ is
A. $2$
B. $3$
C. $4$
D. $1$

Answer 1

Metamers are the compounds having the same molecular formula but different number of carbon atoms on both the sides of the functional group of the particular compound or element.

Complete step by step answer:
Metamers have the same number of carbon atoms but different functional groups making it’s properties really different from one another.
They can also be said to have different spatial arrangement having different functional groups and depending upon how many carbon and hydrogen atoms are on either side of the functional group like -O-, -S-, -NH-, -C(=O)-, amides, esters, etc. they differ.
The phenomenon by which these elements show this property is known as metamerism.
${{C}_{4}}{{H}_{10}}O$ is an ether of the form R-O-R’ where R and R’ can be the same or different.
By arranging different carbon atoms on both the sides of O we can obtain different ethers and hgence different metamers.
${{C}_{4}}{{H}_{10}}O$ can be arranged in three different metameric forms namely $1$-methoxy propane, $2$-methoxy propane and ethoxyethane.
$1$-methoxy propane or methoxy propane is $C{{H}_{3}}-O-C{{H}_{2}}-C{{H}_{2}}-C{{H}_{3}}$ [I]
$2$-methoxy propane is $C{{H}_{3}}-O-CH-{{(C{{H}_{3}})}_{2}}$ [II]
and ethoxyethane is $C{{H}_{3}}-C{{H}_{2}}-O-C{{H}_{2}}-C{{H}_{3}}$ [III].
Here, I and III, II and III are pairs of metamers.

hence option B is correct.

Note: You can make different compounds by changing the number of atoms just make sure you don’t repeat the same molecule and count it as different. We can start the numbering from any side left or right of the oxygen atom so $C{{H}_{3}}-O-C{{H}_{2}}-C{{H}_{2}}-C{{H}_{3}}$ is same as $C{{H}_{3}}-C{{H}_{2}}-C{{H}_{2}}-O-C{{H}_{3}}$ so make sure not to make any mistake like this.