Exp212

=Researcher= Tim Bohinski =Objective= To measure the solubility of p-nitrobenzaldehyde in different solvents.. For a justification of this project see [|here].

=Procedure= Saturated solutions are made of PNBA ([|link to ChemSpider]) in different solvents by charging a one dram vail with 900ul of the solvent. PNBA is then added until the solution is saturated. Each vial is vortexed for 30s. Also each vial is centrifuged for 1-2minutes. 300ul of the liquor is then pipetted into half dram preweighed vials. The solution is weighed and entered into the speedvac. The solution is then reweighed after all of the liquid has evaporated off. The results can be found in the [|Spreadsheet].

=Results= The results can be found in the [|Spreadsheet] Pictures will posted as soon as camera software gets fixed via Khalid. Failure of camera to retrieve pictures. PNBA in acetonitrile:1.06M PNBA in methanol: 0.398M PNBA in chloroform: 1.08M PNBA in ethanol: 0.131M PNBA in toluene: 0.374M Other findings using the same solute and solvents can be found in this article. [|Private Access].

=Discussion= Vial 3b was hard to charge with solution since some solute may have entered the pipet. [|Spreadsheet]. Previous runs showed a decrease in pressure during Exp208. For Exp212 a new pump in the speedvac was used and the pressure didn't change during the experiment. However powders were still obtained from the saturated solutions. Thus a drop in pressure in the speedvac doesn't mean powders can't be obtained. The solutions may have to be held on the vortex longer to see if any further dissovling occurs, since the only result that matches with other findings is when chloroform was the solvent. In Exp208 vials that were designated for PNBA was aborted since it was believed that enough solute was available. I wanted to see experimentally if there was enough PNBA, and there was since this experiment was performed. PNBA as found in the published papers is as follows: PNBA in acetonitrile: [|1.350M] PNBA in methanol: [|1.23M] PNBA in chloroform: [|1.08M] PNBA in ethanol: [|0.376M] PNBA in toluene: [|0.467M]

=Conclusion= Solutions will be vortexed longer to see if the saturated solutions' concentration can be increased.
 * [Ethanol and methanol values marked as "solute reacts with solvent" since hemiacetal likely forms JCB]**

=Log= 11:00 Charged one dram vials with 900ul of each solvent 11:10 Charged each solvent with PNBA. 11:15 Vortexed each for 30 seconds, making sure solution was saturated. 11:20 Centrigued each solution for one minute 11:21 Labeled half dram vials 11:25 Weighed half dram vials. 11:37 Picture was taken of vials. (212p1) 11:40 Pippetted 300ul of each saturated solution into duplicated half dram vials 11:50 Weighed the half dram vials 12:00 Took picture of vials. (212p2) 12:05 Entered half dram vials into speedvac. Pressure (5Torr) 13:00 Removed from speedvac, and reweighed. 14:00 Took a picture of powders in vial. (212p3)
 * 2008-10-31**