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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Shaun1979 on October 27, 2009, 02:58:05 PM

Title: Methyl group mayhem
Post by: Shaun1979 on October 27, 2009, 02:58:05 PM

Hi!

This one should be fairly straight forward, but it has me slightly confused  ???

How many methyl groups in:

-2,4-dimethylpentane
-Propane
-C3H7Br

Is it
-2,4-dimethylpentane....4
-propane...2
-C3H7Br...2

Or
-2,4-dimethylpentane.....2
-propane...0
-C3H7Br...0

Title: Re: Methyl group mayhem
Post by: Dan on October 27, 2009, 03:16:26 PM

Quote from: Shaun1979 on October 27, 2009, 02:58:05 PM

How many methyl groups in:
Is it
-2,4-dimethylpentane....4
-propane...2

yes

Quote

-C3H7Br...2

Could be, it depends which isomer it is.

Title: Re: Methyl group mayhem
Post by: blue eyed on October 27, 2009, 03:35:18 PM

propane is CH3-CH2-CH3.
do we concider CH3 as a group???? I don't think so, because it is part of the main chain.

Title: Re: Methyl group mayhem
Post by: Dan on October 27, 2009, 03:47:04 PM

Quote from: blue eyed on October 27, 2009, 03:35:18 PM

propane is CH3-CH2-CH3.
do we concider CH3 as a group???? I don't think so, because it is part of the main chain.

I see what you're saying, but I'd still consider it a methyl group whether or not it's on a branch or in the main chain. CH₃ = methyl.