Question

What is the condensed formula of the five isomers of $ {{C}_{6}}{{H}_{14}} $ ?

Answer 1

Hint :We know that the isomers which have the same molecular formula and difference in their arrangement of carbon atoms in a chain are called chain isomers. Chain isomerism is possible in case of the compounds having more than two carbon atoms.

Complete Step By Step Answer:
In the question it is given that to draw the chain isomers of hexane. The molecular formula of hexane is $ {{C}_{6}}{{H}_{14}}. $ Means there are six carbons and $ 14 $ hydrogens in hexane molecular formula. The possible structures of the chain isomers for hexane with the molecular formula are as follows:
 $ \left[ {{H}_{3}}C{{\left( C{{H}_{2}} \right)}_{4}}C{{H}_{3}} \right],\left[ {{H}_{3}}C{{\left( C{{H}_{2}} \right)}_{3}}{{\left( C{{H}_{3}} \right)}_{2}} \right],\left[ HC\left( CH_{3}^{{}} \right){{\left( C{{H}_{2}}C{{H}_{3}} \right)}_{2}} \right], $
 $ \left[ {{\left( {{H}_{3}}C \right)}_{2}}CHCH\left( C{{H}_{3}} \right)_{2}^{{}} \right],\left[ C{{\left( C{{H}_{3}} \right)}_{3}}\left( C{{H}_{2}}C{{H}_{3}} \right) \right]. $
We know that the compound is an acyclic alkane, since it has a chemical formula of the $ Cn\cdot H2n+2, $ where n is six in this case.
There are only a finite number of such alkanes. To avoid missing out on any, it pays to do things systematically. We usually go in decreasing lengths of the longest carbon chain. So first it is the longest carbon chain $ =\text{ }6, $ which corresponds to n-hexane. From the above structures we can say that there are five isomers possible for hexane. The five isomers possible for hexane are
 $ \left( n-hexane \right),\text{ }\left( 2-methyl\text{ }pentane \right),\text{ }\left( 3-methyl\text{ }pentane \right),\text{ }\left( 2,\text{ }3-dimethylbutane \right) $ and $ \left( 2,\text{ }2-dimethylbutane. \right) $
These five isomers are called constitutional isomers because each structure contains the same number of carbon atoms and the same number of hydrogen atoms. -The above five structures have the same molecular formula but different in the arrangement of carbon atoms in the main chain.

Note :
Remember that the number of possible arrangements of carbon atoms in the main chain produces the isomers of the compound. The chain isomers will have the same molecular formula but have differences in the arrangement of the carbon atoms with respect to chain.