Objective

To estimate the solubility of diphenylacetic acid in Methanol, Ethanol, Acetonitrile, THF, Toluene, and DMSO.

Procedure

In six different solvents, a saturated solution of Diphenylacetic Acid was made. For instance, a few crystals of the solute were added to six of one dram vials. About 200uL of the six major solvents: Methanol, Ethanol, Acetonitrile,THF, Toluene and DMSO was added to the vials. The one dram vials were labeled as A1 to F1. Later the vials were vortexed and placed into the sonicator for 30 minutes. Temperature was recorded before and after sonication. It was observed that vial F-1 was to be revortexed and resonicated because the solute got dissolved completely in the solent. Next, pictures were taken The vials were later centrifuged while the vials depicted the clear distinguishment between the solute and solvent. After centrifugation, the vials were decanted into new vials A-2 and F-2. Later, choloroform D was added to six new clean dry test tubes and then the supernatent. Finally, the testubes were taken for the NMR test and the results are as shown below.

Results

Pictures


Pic-a
Pic-b
Pic-c
HNMR
ONSCExp081-A2
ONSCExp081-B2
ONSCExp081-C2
ONSCExp081-D2
ONSCExp081-E3
ONSCExp081-F2[is this supposed tobe F2? JCB] yes
Spreadsheet

Discussion

Compared to Exp 077, the concentration of the solvent methanol was 2.29M, while the concentration of the present experiment was 1.18M. [Which value do you think is more likely to be closer to the actual value? JCB] 1.18M is the value that is more likely to be closer to the actual value. The base-line and peaks of this experiment was much clearer than Exp 077.In this experiment, the vials had to be revortexed and resonicated for better results. Trial and error strategies were followed in this experiment.

Conclusion

[You have enough to conclude this experiment JCB] The solubility of Diphenylacetic acid has been determined in the six major solvents such as: Methanol,Ethanol,Acetonitrile, THF, toluene, and DMSO.
[Link to solubility web page, see e.g. References Section in: **http://onschallenge.wikispaces.com/JennyHale-6** AL]

Log


04-20-2009
12:45 Labeled 6 -dram from A1 to F1.
12:50 Placed a small amount of the chemical, Diphenyl acetic acid into each vial.
13:00 Pippeted out 200uL of the six primary solvents; namely, methanol Vial-A, ethanol Vial-B, acetonitrile Vial-C, THF Vial-D, toluene Vial-E, DMSO Vial-F into the each respective vial.
13:10 Vortexed each vial for 30 seconds.
13:15 Placed vials in the sonicator for 30 minutes and the temperature recorded - 25C
13:45 Pictures obtained after sonication and centrifugation as follows. These pictures are labeled as: Pic-a, Pic-b and Pic-c.The pics were not taken in order. For instance,pic-a was taken at 14:53pm, pic-b was taken at 14:42pm and pic-c was taken at 15:06pm. [OK now put these in the right order in the log - you can't have an entry at 15:06 before 13:55, right? JCB]Yes.
13:55 Removed vials from the sonicator.
14:20 Revortexed vial F-1 since the content in the vial hardened, then more solvent was added and then resonicated the vial for 20 minutes, temperature was recorded to be 28C.
14:42 Took pic-b after the vials were sonicated the first time and revortexification.
14:50 Removed vial F-1 from the sonicator.The temperature recorded was 31C.[you should sonicate for at least 30 mins - 20 mins is too short JCB]
14:53 Took pic-a with vials A1-F1 after sonification.
14:55 Centrifuged vials A1 - F1 for 5 minutes.
15:06 Took pic-C of vials A1-F1 and A2-F2 after centrifugation
15:10 Decanted the solid from the solvent into new vials A-2 to F-2.
15:25 Added chloroform-D into 6 clean and dry test tubes and then added the supernatent.
15:35 Recentrifuged vial E-2 in a new vial E-3 for better results, since the solute was not clearly observed to be separated from the solvent. [does that mean you added solid to the NMR tube from E-2 at 3:25? JCB] The supernatent was added to the NMR tube not only from E-2 to E-3 but also from A-2, B-2, C-2, D-2, and F-2.
17:45 Took NMR for this experiment as in ONSCExp081-A2,ONSCExp081-B2,ONSCExp081C-2,ONSCExp081-D2,ONSCExp081-E3,ONSC and Exp081-F2.