Question

: The hydrocarbon containing continuous chain which is isomeric with 2-methyl-3-ethyl hexane is:
A.Hexane
B.Octane
C.Nonane
D.Decane

Answer 1

To answer this question, you should recall the concept of structural isomerism. When the position of substituent groups are changed but the compound has similar chemical formula, it is known as structural isomerism. The continuous chain will contain all the total carbons of the isomer in a single chain.

Complete step by step answer:
We know that isomers are defined as the molecules with the same molecular formula but possess a different arrangement of the atoms in space or different connectivity of atoms. Broadly isomers can be structural or stereoisomers. The phenomenon in which the molecules in which the atoms that form the isomers are connected differently is known as structural isomerism. The phenomenon in which the connectivity of atoms is the same in isomers but a different spatial arrangement is a stereoisomerism.
We know from the nomenclature of carbon compounds based on the number of carbons: Hexane (6 carbon), Octane (8 carbon), Nonane (9 carbon) and Decane (10 carbon).
As, the number of carbons in the isomers should be equal, So 2-methyl-3-ethyl hexane is isomeric with nonane.

Hence, the correct answer is option C.

Note:
Geometric isomerism is one of the forms of stereoisomerism. The key point in geometrical isomers is the restricted rotation of a bond present somewhere in a molecule. At the most basic level of organic chemistry, carbon-carbon double bond is one of the examples leading to a restricted rotation. For example, 2-Butene can exist as cis and trans isomers because of the double bond that leads to the restricted rotation. This results in two isomers where the cis-isomer formed have the two methyl groups on the same side and the trans-isomer formed has the two methyl groups on opposite sides. 2-methyl propene and 2-methyl-2-butene contain a double bond but the groups attached to one of the carbons of the double bond are the same.