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

128-A

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.

128-5A

Vial 5 after having just been placed in heating-cooling thermostat with 60% water and propylene glycol bath set to 43C

128-5B

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.

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.

2009-07-27
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.