Researcher

Evan Curtin

Objective

To determine the solubility of benzalaniline in n-hexane (1), ethyl acetate (2), isopropanol (3), dichloromethane (4), and benzene (5) to compare against the predictions of the Abraham solubility model.

Procedure

Results

SAMS Spreadsheet
The solubility of benzalaniline at 29C is:
in n-hexane: 1.469 M
in isopropanol: 1.431 M
[Report which solvents gave gels too. JCB]

Discussion

The solubility for benzalaniline in n-hexane and isopropanol at 29C was determined, and compared to the Abraham model's predictions. Predictions of 1.203 M (hexane) and 0.725 M (isopropanol) were found to be relatively accurate when compared to experimentally determined solubilities. The difference between the predicted and experimental solubilities for hexane was 0.266 (18.12%) and for isopropanol was 0.706 (49.34%). It should also be noted that the solubilities were recorded at 29C, which would result in a higher solubility measurement. With this in mind, the predictions are even closer than the numbers suggest.

Conclusion

The solubilities of benzalaniline in n-hexane and isopropanol were measured at 29C to be 1.469 M and 1.431 M, respectively. These correlate well with abraham predictions. The remaining 3 measurements were not taken due to gelling.

Log

2011-07-22

12:22 - Mixed roughly 300mg of benzalaniline with 100 to 1000 microliters of each solvent. The sample in dichloromethane dissolved completely. Added more solid until it didn't dissolve completely.
12:48 - Added each sample to a 47C bath.
13:03 - Bath temperature is 51C, each sample is completely dissolved. Removed all samples from bath. Set on counter at RT (29C).
13:30 - 1 had precipitate, the rest did not.
13:36 - Blew air on samples 2-5 until precipitate formed.
14:09 - Samples 2, 4 and 5 made a gel. Attempted to break by stirring with a spatula, but no clear supernatant formed. Heated each sample for 30 seconds, clear solution formed.
14:15 - Blew air on samples 2, 4 and 5. The solid precipitated all at once, and no pure solution could be extracted from any of these 3 samples.
14:17 - Mixed supernatant from samples 1 and 3 with CDCl3 [I later found out that this CDCl3 had no TMS, and am having difficulty assigning a peak to a known ppm - EC]. Added to NMR tube. [That should not be an issue - you can look up the solvent peaks or the solute peaks and use that as a ref. Lets take a look: upload the spectra. JCB]
14:35 - Took HNMR of 1 and 3 using 500MHz varian NMR.