Did I name the functional groups that are present in the following molecules correctly? All I was given is the picture below. I have drawn my attempt in the picture.

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Edit1: response to k--

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Edit2: response to Mithoron

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  • $\begingroup$ second version is worse than first... $\endgroup$ – Mithoron Sep 22 '15 at 13:51
  • $\begingroup$ @Mithoron. Can you please tell me where I messed up? $\endgroup$ – Ro Siv Sep 22 '15 at 20:59
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    $\begingroup$ Basically what k told in comment. Functional groups are heteroatoms with hydrogens or carbons double/triple bonded. Carbons with only single bonds are part of alkil (methyl itp.) groups, not other groups. Substituted aromatic rings belong to aryl (phenyl, phenylene itp.) groups. $\endgroup$ – Mithoron Sep 22 '15 at 21:50
  • $\begingroup$ Btw you can make better pictures with IsisDraw, ChemSketch, Inkscape or other free programs. $\endgroup$ – Mithoron Sep 22 '15 at 21:52
  • $\begingroup$ @Mithoron I included an updated drawing, if you could check it I would appreciate it. Sorry I didnt use those chemistry drawing programs you suggested, but I didnt think I had the time to fuss with them. I am bad at learning new things when I have alot on my plate. Thanks for the advice. $\endgroup$ – Ro Siv Sep 22 '15 at 22:48

First molecule: The ester group is correct - you have a carbonyl (C=O) carbon bonded to an oxygen and both sides are bonded to an R group (any carbon/hydrogen group).

Phenol is incorrect - for a phenol group, the hydroxy/OH must be directly bonded to the ring, like so:

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So instead, what you've labelled comprises of two functional groups: the ring is an arene group, and the OH is a hydroxy/alchohol group.

You haven't labelled the two branch alkyl group on the left of the molecule - this is called an isopropyl group (it has three carbons, so it's basically a propyl group with something attached to the middle carbon). This group might not always be considered a functional group though (maybe ask your lecturer?). Or it can just be called an alkane group.

Second molecule: The amide group is pretty much correct, except it should only include at most the atoms bonded directly to the nitrogen and carbonyl carbon.

The alkene should only include the double bond (while the whole chain could be considered an alkene, the alkene functional group only contains the double bond).

One that you haven't included is the ether group, R-O-R.

To learn these I would suggest just using a table of common functional groups until you start to remember them. I think the Wikipedia page is good because you can look at your molecule and see what unusual atoms you have (e.g. nitrogen, oxygen) and see if any of the groups under that heading look like they're in your molecule, except it might be missing a few e.g. phenol.

  • $\begingroup$ Could you see if my edited response was accurate? Thank you. And my teacher did give me a table of common organic functional groups, I guess I just have problems telling where one ends and another begins. He suggested memorizing them for our exam though, which I plan to do. $\endgroup$ – Ro Siv Sep 22 '15 at 1:25
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    $\begingroup$ I would say that functional groups end where the R group begins, so e.g. if you have the functional group R-OH, the actual functional group is just the OH bit plus maybe the first atom the OH is connected to, rather than the rest of the alkyl chain like you've circled. Sorry if I wasn't clear but you had the amide group right the first time - with the nitrogen and the C=O part. The ether group I was talking about is actually the oxygen in the ring: R-O-R. The rest seems good though. $\endgroup$ – k-- Sep 22 '15 at 3:03

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