[Plumbum]

hi

I have to analyzes an unknown mixture consisting of two liquids in my oc labrotory.

I have the following clues :

Ph: 5
No color
Absolute no smell
 And the IR.

I don't really know what I can do now cut my if doesn't show so much. Do I have  an alcohol ? Thank u

[Dan]

I have the following clues :

Ph: 5
No color
Absolute no smell
 And the IR.

I don't really know what I can do now cut my if doesn't show so much. Do I have  an alcohol ? Thank u

There is not enough information here to identify two unknowns. But I suppose you could suggest a composition that is consistent with the data.

What does the pH suggest?

Side point: Did you measure the pH yourself or was it given to you? If you measured it yourself, how did you do it - neat or in aqueous solution?

[pgk]

By a first view, this IR spectrum indicates an alcohol or an amine that contain both methyl and methylene/methyne groups. Amine must be excluded due to the low pH. The strong hydoxyl peak indicates a small molecule but small alcohols have a characteristic odor.Thus, the absence of odor indicates a small polyol (diol or triol). Besides, the content ratio of methyl and methylene groups as it figures, might be due a mixture with another liquid. In other words, information is not enough for the safe determination of the structure.

[Plumbum]

i have some further information maybe u can tell me how i should continue cuz i am absolutely clueless at this point.

My solution dissolves in water, 5% Hcl,5% NaOH and 5% Sodium bicarbonate solution.
It doesnt dissolve in Diethyl ether, whereas my solution in the bottom and Diethyl ether above.
I tried to distill it, my solution became kinda yellow...it didnt work though.My temperature didnt raise higher than 60 °C for some reason. So the boiling point from both solutions mustbe above 60 °C.

help

[pgk]

Which small alcohol or polyol is insoluble or slightly soluble in diethyl ether and do not smell? There must not be too many.
Are you sure that your sample does not decompose during distillation?
Which small alcohol or polyol decomposes during (quick) distillation? There must not be too many.
Which might be the potential decomposition product that boils near 60oC?
Did you run an IR spectrum of the distillate? (Do not smell it because it might be toxic).
Did you compare the given IR spectrum with other IR ones of small alcohols or polyols, which can be found in the web?
PS: Given that information is still not enough, all above might not be to the right direction but they must be explored. 

[Dan]

The pH 5 is difficult to account for.

This is why I asked:

Side point: Did you measure the pH yourself or was it given to you? If you measured it yourself, how did you do it - neat or in aqueous solution?

because the result will be misleading if it was not measured in aqueous solution.

[Plumbum]

I measured it myself in aqueous solution.

Do you agree with me that I can pretty much exclude the other functional groups excecpt for alcohol and amine due to the IR? If so, I could simply test for amine

[pgk]

You do not have carbonyls, nor unsymmetrical triple bonds or allenes, neither aromatics. Apart these, you cannot exclude other functional groups because the IR spectrum is not an absolute criterion of the structure, except if it coincides with the one of a known compound (even so, it is not 100% safe). But before excluding anything, try to answer the above questions. 

[discodermolide]

Does it react with FeCl₃ solution?

[Plumbum]

Does it react with FeCl₃ solution?

Didnt try that. What does it mean if it does?


@pgk I'll get to your questions later, i gotta do some research.

thanks fo helping me, though!

[discodermolide]

Does it react with FeCl₃ solution?

Didnt try that. What does it mean if it does?

Try google

[Plumbum]

DO you think i might have a phenole?

Right now I suppose I may have an alcohol and an ether.

[Plumbum]

Let me tell you what I did today.:

I gave FeCl3 to my solution -> negative , no phenole.
No Ether, cuz it doesnt dissolve in Diethylether.
Rojahn was negative
Test for aromate was negative as well..
my test for alcohol was positiv though but that was obvious.

So I came to the coclusion that both of my solutions must be alcohol with a very high boiling point!

I also made a vacuum destillation. It boiled finally at 150 °C, and the IR looks like that:

Im pretty desperate at this point and have no idea what to do next.

[phth]

You can infer symmetry from the CH/CH2/CH3 peaks in the spectrum.  If possible the first step which is missing is to take a mass spec and narrow down the formula, so we have something easier to work with.

[pgk]

 It was mentioned above that you do not have aromatics (that appear near 1600 cm-1).