[yoyodude91]

I've been working on this for a long time and cannot figure out what the compound is. Whenever I think I figured it out (the NMR has been what I've looked at the most when trying to figure it out), I look up the compound and see that its standard NMR is completely different from mine. If anyone has any ideas or any advice on how I can come closer to figuring this out, I would really appreciate it.

-It's a clear liquid with a strong smell.
-pH = 4.
-I calculated density to 0.983.
-refractive index is around 1.498 (when i took it, the value was between 1.490 and 1.500. It was closer to 1.500).

A picture of the IR is on the following link:
http://s1248.photobucket.com/albums/hh483/yoyodude91/Chemistry/?action=view&current=IR.jpg

A picture of the NMR is on the following link: http://s1248.photobucket.com/albums/hh483/yoyodude91/Chemistry/?action=view&current=IR.jpg#!oZZ2QQcurrentZZhttp%3A%2F%2Fs1248.photobucket.com%2Falbums%2Fhh483%2Fyoyodude91%2FChemistry%2F%3Faction%3Dview%26current%3DNMR.jpg

Thank you. 

[Arkcon]

Here are the pics.  'Tho you might want to instead interpret the peaks in the IR for us, its a little small.

[Arctic-Nation]

Wow, haven't seen such an NMR since I was an undergrad. I take it the spectrum has been calibrated to 1.000 instead of 0.000, otherwise the thing doesn't make any sense. You've also not included the solvent, which is a big no-no when interpreting spectra. If the solvent is deuterochloroform, that's the big peak at 7.24 ppm (8.24 in your spectrum).
Further, you've got an ethyl group and an isolated methylene (possibly methyl, but I'm not going to put a ruler to my screen).  No idea what the marked peak at 4.3 is. You've included a pH value, by which I assume the pKa, and this tells us you probably have a carboxylic acid, even though the value is on the low side. The carbonyl group is the big peak at 1730 cm-1 in the IR.

All this combined, things are pointing at something like CH3-CH2-O-CH2-COOH, but I might be way off.

Is this is a compound you've made yourself? If so, it'll help us if you could post your reaction procedure. And a mass spectrum. And for the love of all that is good and holy, a normal NMR spectrum.

[yoyodude91]

I'm sorry, I completely forgot to include the solvent I used. You're right, it was deuterochloroform.

And no, I didn't make the compound myself. We all received an unknown liquid or solid that we need to identify. I made the NMR solution with the deuterochloroform and my professor actually performed the NMR. I only got the IR myself.

Thank you for the information you provided though. I've been thinking that it might be lactic acid, but I'm not too sure.

[yoyodude91]

Also,

Here are some of the peaks in the IR.

-3000: I think this in an OH bond with many little CH bonds
-1720: I think this is the C=O bond
**therefore, I'm pretty sure my compound has a carboxylic acid. Since the ph is 4, I believe it's a weak acid.

-1600
-one small one around 3200
-there are many bonds in the fingerprint region between 1000 and 1500: I believe they could be C-O bonds, but I'm not sure what other possibilities there could be

[Furanone]

What does it smell like?

[yoyodude91]

I'm sorry, I'm can't really describe. It's a strong smell, so I definitely believe it's a type of acid. However, i's difficult for me to explain it.

I also took the boiling point and got 70 degrees celsius. However, I had to rush through it at the end of the period, so I'm not too confident in how accurate the value is.

[Arctic-Nation]

A boiling point of 70°C? That's too low for carboxylic acids; even acetic acid boils at about 120°C. You sure the pKa value is correct?

No chance of getting a mass spectrum? And could you give us the exact integration of the two single peaks around 4.5 ppm in the NMR spectrum?

[fledarmus]

Thank you for the information you provided though. I've been thinking that it might be lactic acid, but I'm not too sure.

You might want to look up the properties of lactic acid. It is not a liquid at room temperature, and certainly doesn't boil at 70C

[yoyodude91]

You're right. I decided to ignore the boiling point I obtained because I really don't think it's accurate. I had to rush through it and I boiled water to heat the solution instead of using a thermowell. Therefore, if the boiling point was higher than 100, I wouldn't have been able to see it anyway.

I've been thinking that it might be butyric aka butanoic acid.

[AWK]

?
http://www.ces.clemson.edu/IMMEX/backup/asif/Spectra/Case9/example_spectra/ex_2but_hnmr.htm

[yoyodude91]

That NMR actully looks pretty close. But when looking at my IR, do you think all the bands between 1000 and 1500 indicate an ester group?

[AWK]

Your IR is very bad.
http://chemwiki.ucdavis.edu/Wikitexts/UCD_Chem_205:_Larsen/ChemWiki_Module_Topics/Infrared:_Interpretation

[discodermolide]

That NMR actully looks pretty close. But when looking at my IR, do you think all the bands between 1000 and 1500 indicate an ester group?

I think you need to brush up on your experimental techniques. Unless you get useful information you are just making wild guesses.
Measuring a BPt. by putting the compound in a beaker of boiling water is not good experimental methodology.
Try making your NMR solutions a bit more concentrated and ask someone who knows how to use the machine to run it for you, not some pencil pushing Prof. Then you may get useful info. from it.

[orgopete]

Although I agree that these spectra could have been better, I think they are sufficiently acceptable to determine a structure. I suggest you determine a hydrogen ratio from the NMR. Hydrogens come in 1s, 2s, and 3s. It has already been suggested that you have an ethyl group. Therefore you know that there is XH, 2H, YH, 3H. What are or could be X and Y? The big peak at 7.24 is not chloroform, it is your compound. Determining X and Y from the integral should give a big clue. You virtually have only two or three atoms to move around. Draw out some possibilities with those atoms.

If you can re-run your IR, do so. It is much too strong to make a comparison with authentic samples. You will find authentic samples do not max out the absorbance at every peak as the posted spectrum has. If you cannot re-run it, it is still good enough, but you need to mentally reduce the absorbances. What are big peaks in your spectrum are actually small peaks in an authentic spectrum.

Look at the "Tinker Toy" method I was suggesting in this problem. Look at your spectrum. Write down on paper what each piece could be. If you have a CH3 group, what must it be attached to? What other groups can you discern? Can you tell what atoms they may be attached to? If you have more than one possibility, write them down in a group.

Hint, there isn't any absorption at <3050 cm^-1 and your compound only contains C, H, and O. When I put the pieces together, I could only come up with one possibility. I don't know how many anyone else may come up with, but I cannot emphasize enough to write on paper the pieces you are trying to place and some possible structures. You can test possible structures against your spectral data and decide if a piece is right, nearly right, could be right with some adjustment, or can be excluded. Your NMR has four signals and two you know something about. There are two additional signals you should be able to figure out from the integral. There are some additional atoms that do not give signals in the NMR, but the chemical shifts and IR certainly strongly suggest what they are. Given that information, it shouldn't be that hard (provided you write something on paper).