Exp119

=**Researchers**= Matthew Federici and Catherine Cho

To generate a solubility-temperature curve for 3,4 methylenedioxyphenylacetic acid in methanol. media type="custom" key="4059269"
 * Objective**

**Procedure**
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 * [|Spreadsheet]**



**Results**
There were no results from this experiment.

=Conclusion= While there were no results for this experiment, it can be concluded that vials must stay "cap up" when in the temperature bath. Otherwise, precipitation cannot be easily observed. Perhaps if a larger solution of 3,4 methylenedioxyphenylacetic acid and methanol is made and placed in the half dram vials, precipitation may be easier to observe.
 * [good - anything you can learn from an experiment is helpful even if you don't achieve your objective JCB]**

**Log**
2009-07-07 09:37: 5 half dram vials were labeled 1, 2, 3, 4, and 5. 09:39: 250 micoliters of methanol was placed into each vial using a micro pipette.**[weigh the solvent don't use volume because micropipettes are not calibrated for organic solvents JCB]** 09:48: Weighing paper was placed into an Adventurer Pro scale and zeroed. 31.9mg of 3,4 methylenedioxyphenylacetic acid was weighed in the scale and funneled into vial 1. This created a 0.5 molar solution. 09:56: Another piece of weighing paper was placed in the scale and zeroed. 67mg of 3,4 methylenedioxyphenylacetic acid was weighed in the scale and funneled into vial 2. This created a 1 molar solution. 10:06: Another piece of weighing paper was placed in the scale and zeroed. 108mg of 3,4 methylenedioxyphenylacetic acid was weighed in the scale and funneled into vial 3. This created a 1.5 molar solution. 10:12: Another piece of weighing paper was placed in the scale and zeroed. 158.6mg of 3,4 methylenedioxyphenylacetic acid was weighed in the scale and funneled into vial 4. This created a 2 molar solution. 10:19: Another piece of weighing paper was placed in the scale and zeroed. 218.6mg of 3,4 methylenedioxyphenylacetic acid was weighed in the scale and funneled into vial 5. This created a 2.5 molar solution. 10:22: Vials 1, 2, 3, 4, and 5 were placed in the sonicator. The sonicator temperature was 37C and the timer was set for 10 minutes. 10:25: All vials were removed from the sonicator. There was not any visible precipitate in any of the vials. 21:30: Labels were made for each vial. The labels were tied to each vial so they could be easily recognized. 21:37: The Lauda 4K/R was set to 40C. 21:57: Vials 1, 2, 3, 4, and 5 were placed in the bath. 22:05: The bath temperature was lowered to 38C. There was no visible precipitation. 22:12: The bath temperature was lowered to 36C. There was no visible precipitation. 22:20: The bath temperature was lowered to 32C. There was no visible precipitation. 22:30: The bath temperature was lowered to 27C. There was no visible precipitation. The vials were taken out of the bath and placed in an empty beaker.

2009-07-09 21:04: All vials were placed in the sonicator. The sonicator temperature was 41C and the timer was set for 10 minutes. 21:16: All vials were removed from the sonicator and placed in a 3:2 water to ethylene glycol bath. There was no precipitation in any of the 5 vials. The thermostat in the bath measured to temperature to be 40C. 21:39: The bath temperature was lowered to 27C. 22:00: No precipitation was observed at 27C. The bath temperature was lowered to 25C. 22:30: No precipitation was observed at 25C. The bath temperature was lowered to 23C. 22:45: No precipitation was observed at 23C. The bath temperature was lowered to 21C. 23:00: No precipitation was observed at 21C. The bath temperature was lowered to 19C. 23:15: No precipitation was observed at 19C. The bath temperature was lowered to 17C. 23:22: No precipitation was observed at 17C. The bath temperature was lowered to 15C. 23:33: No precipitation was observed at 15C. The bath temperature was lowered to 10C. 23:40: No precipitation was observed at 10C. The bath temperature was lowered to 5C. 23:49: No precipitation was observed at 5C. The bath temperature was lowered to 0C. 23:57: No precipitation was observed at 0C. The bath temperature was lowered to -5C. 00:11: No precipitation was observed at -5C. The bath temperature was lowered to -10C. 00:18: All of the vials were taken out of the bath. After inspecting vial 5, it was discovered that some crystallization had formed around the top of the vial. The vial must have inverted in the bath and precipitation occurred at the top of the vial. With parafilm covering the top of the vial, this could not easily have been observed. All vials were placed in a 250mL beaker filled with water. The water was room temperature, 23C.**[Yes I can see that ppt forming in the cap is problematic for small volumes - I suggest maybe using a kind of holder that would keep the vials tilted with the caps pointing up and stay sunk - possibly Wolfgang on the 6th floor could rig something up JCB]**