ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: destain on May 12, 2012, 10:14:53 am
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With the NH2 group,
Do you go aminohexane or hexylamine or are they both acceptable and also
if it's with hexylamine, do you mention it as 1-hexylamine if it is on the first carbon? or you're allowed to simply go hexylamine since it is on the first
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hexylamine would be correct
1-hexylamine would be better (less ambiguous)
Best would be hexan-1-amine (follows IUPAC naming system)
If you had a secondary amine, e.g. CH3-NH-CH2CH2CH3, you would name it N-methylpropanamine, stemming from the nitrogen.
Tertiary amines would be similar to secondary, you would get something like N-methyl-N-ethylpropanamine (i.e. methyl,ethyl and propyl groups stemming from the Nitrogen)
Not sure if you guys need to name secondary/tertiary amines, but it's good to know just in case.
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Would take a mark off for hexylamine if I were an examiner, by the way. You really do need to specify where the NH2 group is going.
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They would accept hexylamine, aminohexane or hexanamine if the NH2 is substituted on the first carbon. I'm pretty sure it's been tested in exams before and they would've accepted any of those answers.
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^ i thought aminohexane was wrong unless there was another functional group which had priority e.g
1- amino - hexanoic acid
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Yeah technically (by IUPAC nomenclature) you would want to name it as hexan-1-amine, but I'm just saying, the examiner will mark all 3 options as correct.
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For naming the end part of the molecule, the precedence is: acid>alcohol> amino
Therefore if you have say n-hexanoic acid with a NH2 group attached to the second carbon, it would be 2-amino hexanoic acid....
Otherwise, if there is an amino functional group but no acid or alcohol groups, the amino takes precedence and the end naming is according the position of the amino group....ie hexan-2-amine.