Exp128

=media type="custom" key="4175891"= = = =Researcher= Jenna Mancinelli

=Objective= To generate a solubility-temperature curve for 4-nitrobenzaldehyde in a mixture of solvents: acetonitrile, THF, toluene, and chloroform.

=Procedure= Label five vials. To each vial add the appropriate amount of each of the four solvents: acetonitrile, THF, toluene, and chloroform. Add the appropriate amount of 4-nitrobenzaldehyde to each mixture of solvents. Parafilm each vial tightly, and vortex. After labeling each vial, place them in a heating-cooling thermostat with 60% water and propylene glycol bath set to 43C until mixtures are homogenous, unsaturated solutions. Once this occurs, drop the temperature and record the temperature at which each mixture precipitates.

=Results= [|Spreadsheet]

media type="custom" key="4147837" Vials 1, 2, 3, and 4 after having been in heating-cooling thermostat with 60% water and propylene glycol bath set to 43C for 1 hr.
 * 128-A**

media type="custom" key="4121703" Vial 5 after having just been placed in heating-cooling thermostat with 60% water and propylene glycol bath set to 43C
 * 128-5A**

media type="custom" key="4121829" Vial 5 after having been heating-cooling thermostat with 60% water and propylene glycol bath set to 43C for more then 10 minutes. Mixture has still not reached solution.
 * 128-5B**

=Discussion= The 4-nitrobenzaldehyde was expected to dissolve completely in the solvent mixtures at a high temperature, after which the temperature could be dropped and the temperature at which 4-nitrobenzaldehyde precipitated out from the mixture recorded. According to the results from Exp111 and Exp114, 4-nitrobenzaldehyde should have precipitated out at varying temperatures for each of the different concentrations.

=Conclusion= A solubility-temperature curve for 4-nitrobenzaldehyde in a mixture of acetonitrile, THF, toluene, and chloroform was not able to be obtained successfully. = = =Log=

2009-07-20
17:00 Mixture of solvent made in vial. 0.023 g acetonitrile, 0.213 g THF, 0.0894 g toluene, and 0.6382 g chloroform. 17:45 0.7033 g 4-nitrobenzaldehyde added to the solvent mixture in the vial. 18:00 Vial tightly parafilmed. Centrifuged and labeled. 18:20 Vial placed in heating-cooling thermostat with 60% water and propylene glycol bath set to 43C 18:25 Took video of vial in bath. 18:00 Mixture in vial had still not reached solution. 18:05 Took second video of vial in bath. 19:00 Mixture will not reach solution within a safe temperature range.

16:00 Labeled four vials 16:15 Added appropriate mixtures of solvents in each vial. 16:45 Added appropriate amount of 4-nitrobenzaldehyde to each solvent mixture. 17:15 Tightly parafilmed each vial. Vortexed each for 10 seconds. 19:00 All four vials placed in heating-cooling thermostat with 60% water and propylene glycol bath set to 43C 19:10 Mixtures still saturated. Vortexed each vial for five seconds and placed back in bath immediately. 19:40 Raised temperature of bath to 45.0C 20:00 Mixtures still saturated. Experiment stopped because mixtures will not reach solution within safe temperature range. Video taken. 20:30 All mixtures poured into one beaker for later recrystallization.
 * 2009-07-27**