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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: KurzickMushroom on September 11, 2009, 07:29:49 PM

Title: Help me name this saturated hydrocarbon! :)
Post by: KurzickMushroom on September 11, 2009, 07:29:49 PM

CH3 C(CH3)(C2H5) CH(C2H5)(CH2)3 CH3


The (CH2)3 near the right hand side is what confuses me. From what I know, each carbon in this structure may only have 4 bonds connected to it.  I don't understand how those 3 methanes are just there.

Thanks in advance.

Title: Re: Help me name this saturated hydrocarbon! :)
Post by: azmanam on September 11, 2009, 08:00:30 PM
(CH2)n is a shortcut for a string of methylene groups - that is, a chain of carbon atoms with two hydrogen atoms attached.  It's just a generic carbon chain with no substituents.  I've redrawn what I think is your molecule.  Did I redraw it correctly?  Can you name it now that it's redrawn?  What is your guess so far?
Title: Re: Help me name this saturated hydrocarbon! :)
Post by: matsci0000 on September 12, 2009, 05:37:06 AM
In condensed form , the formula of organic compounds are written in this way ([n][/sub]CH).It makes the formula shorter.

For example- C5H10 (n-pentane) can be written as CH3 (CH2)3 CH3.

Title: Re: Help me name this saturated hydrocarbon! :)
Post by: cliverlong on September 12, 2009, 06:13:00 AM

CH3 C(CH3)(C2H5) CH(C2H5)(CH2)3 CH3

The (CH2)3 near the right hand side is what confuses me. From what I know, each carbon in this structure may only have 4 bonds connected to it.  I don't understand how those 3 methanes are just there.

Thanks in advance.
When I have to name such a thing I can never work from the condensed form - the version you have been given

I have to draw the structure of the compound. Then I check that all the carbons have 4 bonds (as you wrote). Then I work out the longest carbon chain - that is the backbone - and start naming from there by adding all the side groups.

Clive
Title: Re: Help me name this saturated hydrocarbon! :)
Post by: KurzickMushroom on September 12, 2009, 03:17:13 PM


Thanks all I think I got it now.