March 19, 2024, 01:05:55 AM
Forum Rules: Read This Before Posting


Topic: Unknown mixture 2  (Read 6823 times)

0 Members and 1 Guest are viewing this topic.

Offline Plumbum

  • Full Member
  • ****
  • Posts: 133
  • Mole Snacks: +2/-0
  • Gender: Female
Unknown mixture 2
« on: July 06, 2015, 11:42:44 AM »
hi

So I solved the old one and got a new one. Thanks so much to everyone who helped me. I now have my final analysis. Three substances are in it. I already know one for sure : citronellol.

I can't quite tell what functional groups I might have.

It looks like I might have an aromate, Not quite sure about a carbonyle peak is it one ?


I didn't Do any tests yet, the solution is neutral. The solution doesn't dissolve in water but it does in diethylether.
What functional groups might I have?

Thx
There might be some language misunderstandings - I'm from Germany

Offline Arkcon

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 7367
  • Mole Snacks: +533/-147
Re: Unknown mixture 2
« Reply #1 on: July 06, 2015, 12:49:44 PM »
The IR might be the first thing to do, unless you want to fractionally distill, under vac, and isolate your 3 first.  I wouldn't do wet chem for functional groups first, is what I'm saying.
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline Plumbum

  • Full Member
  • ****
  • Posts: 133
  • Mole Snacks: +2/-0
  • Gender: Female
Re: Unknown mixture 2
« Reply #2 on: July 06, 2015, 01:39:41 PM »
I totally forgot to upload my IR ! Here it goes :)
There might be some language misunderstandings - I'm from Germany

Offline Plumbum

  • Full Member
  • ****
  • Posts: 133
  • Mole Snacks: +2/-0
  • Gender: Female
Re: Unknown mixture 2
« Reply #3 on: July 07, 2015, 12:08:01 PM »
Can anyone help me? I'm pretty clueless.

I know one substance for sure which is an aldehyde. I have no halides because there was no precipitates with agno3. I have an aromate though. Maybe alcohol ? Because the test with Ceric ammonium nitrate seems to be positive. Some kind of gas appeared when I was heating it. Something might have react.

I tried to vacuum destilatte it. The ir doesn't looks very differently any ideas what I might have or what I should do next ?

THANK U
There might be some language misunderstandings - I'm from Germany

Offline Plumbum

  • Full Member
  • ****
  • Posts: 133
  • Mole Snacks: +2/-0
  • Gender: Female
Re: Unknown mixture 2
« Reply #4 on: July 07, 2015, 12:17:30 PM »
Those are the irs of my two fractions when I destilated.
There might be some language misunderstandings - I'm from Germany

Offline Plumbum

  • Full Member
  • ****
  • Posts: 133
  • Mole Snacks: +2/-0
  • Gender: Female
Re: Unknown mixture 2
« Reply #5 on: July 07, 2015, 03:35:42 PM »
No Advise ?
There might be some language misunderstandings - I'm from Germany

Offline phth

  • Chemist
  • Full Member
  • *
  • Posts: 528
  • Mole Snacks: +39/-4
Re: Unknown mixture 2
« Reply #6 on: July 07, 2015, 06:31:42 PM »
#2 thing I thought was that it could be an aldehyde with an overtone frequency around (2870 is not, its below 2830cm-1).   The 1512 is phenyl group, 1671 could be benzaldehyde(C=O), but it has to have a strong hydrogen bonding conjugating effect for example 2-hydroxybenzaldehyde<--C=O @ 1665.  We should see line broadening of the aldehyde CO and there are no OH peak.  I see conflicting results with your OH test.

Offline Plumbum

  • Full Member
  • ****
  • Posts: 133
  • Mole Snacks: +2/-0
  • Gender: Female
Re: Unknown mixture 2
« Reply #7 on: July 08, 2015, 01:47:21 AM »
yeah i thought so top i cant have an oh group.

i do have an aldehyde and thst one is citrale i aoready know that. i also have an aromate..

what do you think are nitriles or acetale possibl
There might be some language misunderstandings - I'm from Germany

Offline Plumbum

  • Full Member
  • ****
  • Posts: 133
  • Mole Snacks: +2/-0
  • Gender: Female
Re: Unknown mixture 2
« Reply #8 on: July 08, 2015, 08:26:59 AM »
@phth why do you think benzaldehyde though. the carbonyl peak could be from my citrale
There might be some language misunderstandings - I'm from Germany

Offline phth

  • Chemist
  • Full Member
  • *
  • Posts: 528
  • Mole Snacks: +39/-4
Re: Unknown mixture 2
« Reply #9 on: July 08, 2015, 03:10:47 PM »
i dont understand whats pure and whats not.  conjugated aldehyde is possible, i was saying somthing similar to the picture i posted

Offline Plumbum

  • Full Member
  • ****
  • Posts: 133
  • Mole Snacks: +2/-0
  • Gender: Female
Re: Unknown mixture 2
« Reply #10 on: July 08, 2015, 03:52:49 PM »
oh okay. I do have citrale, thats the aldehyde...

I am not sure about the other substances though =(
There might be some language misunderstandings - I'm from Germany

Offline Plumbum

  • Full Member
  • ****
  • Posts: 133
  • Mole Snacks: +2/-0
  • Gender: Female
Re: Unknown mixture 2
« Reply #11 on: July 08, 2015, 04:10:44 PM »
due to th boiling point ( I had one at 134 and one at 178) and the index of refraction i thought i might have
Ethylbenzene and/or p-cymene
There might be some language misunderstandings - I'm from Germany

Offline phth

  • Chemist
  • Full Member
  • *
  • Posts: 528
  • Mole Snacks: +39/-4
Re: Unknown mixture 2
« Reply #12 on: July 09, 2015, 02:56:39 PM »
para makes sense

Offline Plumbum

  • Full Member
  • ****
  • Posts: 133
  • Mole Snacks: +2/-0
  • Gender: Female
Re: Unknown mixture 2
« Reply #13 on: July 10, 2015, 01:45:12 AM »
I'm still pretty clueless. So I distilated and that's my first fraction. I distilated with vacuum/ 1,5 mbar

I don't think the fractions are absolutely pure but at least they are different.

So here is what I see:


3019-2870: ch stretch in Alkanen
1514: n-o stretch from nitro compounds  ?
1020: c-n stretch from amine  (my test with ninhydrin though was negative)
720: ch stretch from alkanes
541: c-Br (there was no precipitate with agno3 though)
Und 813: c-cl

All contradictory :((

There might be some language misunderstandings - I'm from Germany

Offline Plumbum

  • Full Member
  • ****
  • Posts: 133
  • Mole Snacks: +2/-0
  • Gender: Female
Re: Unknown mixture 2
« Reply #14 on: July 10, 2015, 01:49:25 AM »
Here is the second fraction about 100 Grad/ 1.5 mbar.

What I see :

3421: Alcohol oder Amin, solution wasn't basic that's why I think alcohol
2966/2913: ch in Alkane
2174:alkine
1670: carbonyl
1449/1432: ch in Alkane
1195/1150/1121: CN bei aliphatic amine, solution not basic though.

I also have the refraction index  : 1,501

Please help me out i am so desperate


---------

To sum all up I have :
Solution does dissolve in water not in ether though
I have an aromate
Not basic,ph 4
Compounds are lighter than water
There might be some language misunderstandings - I'm from Germany

Sponsored Links