Five structural isomers, or constitutional isomers, have the formula C6H14 . Draw the indicated isomers, grouped by number of carbon atoms in the main chain. Draw two isomers with 5 carbon atoms in the main chain. Be sure to include all hydrogen atoms.

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Explanation:

For this question, we have to remember that definition of an "isomer" in an isomer we have the same condensed formula (in this case ) and different structures. The first structure is a linear structure of 6 carbons (hexane). Then we can have a 5 carbon linear structure in which we have to add a methyl group. This methyl group can be attached to carbon 2 or carbon 3 (2-methylpentane and 3-methylpentane). Finally, we can have a 4 carbon linear structure in which we have to add 2 methyl groups. We can do this addition in carbon 2 (2,2-dimethylbutane) or we can do this addition in carbon 2 and carbon 3 (2,3-dimethylbutane).

See figure 1

I hope it  helps!