Answer to Question #24459 in Organic Chemistry for Kamakshi Arora

Question

It is said that structural isomers have identical molcular formula but different structures. But hexane has the formula C6H14 and cyclohexane has the formula C6H12, here two hydrogen atoms are reduced. How is it then, that they have similar molecular formula?

Answer 1

They do not have the same formula and so are not constitutional isomers.Cyclohexane is not structural isomer for hexane, It can be isomer for hexene because it has one double bond in it which results in 2 less H, so they both have the& same molecular formula C6H12. Hexane has 5 isomers and cyclohexane is no one of them.