[ashalee]

Okay I have a question on my assignment that asks me to give the condensed structural formula for hexane. So from the hex- I gather that there is a continuous link of 6 carbon atoms, and since it is an alkane, is saturated. I would say that the structural formula would look like this

   H H  H H  H  H
   |  |  |  |  |  |
H-C-C-C-C-C-C-H
   |  |  |  |  |  |
   H H  H  H H  H

and thus render a condensed structural formula of CH3CH2CH2CH2CH2CH3

HOWEVER:

The module I was given clearly shows the molecular, structural and condensed structural formulas of a few compounds including hexane. And this is their idea of a structural formula for hexane, which to me, looks an awful lot like 2,2-dimethylbutane.

         H
         |
      H-C-H
   H H  |  H
   |  |  |  |
H-C-C-C-C-H
   |  |  |  |
   H H  |  H
      H-C-H
         |
         H

can anyone clearify on this?

[Biopolmonkey]

Yes, hexane is as you describe. Think maybe some kind of error on your sheet. (The second structure is also, as you deduced, 2,2-dimethylbutane or neohexane)

[ashalee]

Yes, hexane is as you describe. Think maybe some kind of error on your sheet. (The second structure is also, as you deduced, 2,2-dimethylbutane or neohexane)

So then the structure for 2,2-dimethylbutane, has the same chemical formula as hexane therefore making it an isomer of hexane correct?
still shouldn't they have listed the first configuration as hexane?

[Biopolmonkey]

Yes, they are isomers + I agree the linear should have been the first configuration ... It's certainly what we expect to arrive when we order hexane as a solvent each week!

[Doc Oc]

I believe those are called constitutional isomers (ie; same overall CH formula, but different structures based on the linkage).  2-pentanol and 3-pentanol fall under the same category.