Researcher

Matthew McBride

Objective

To determine the solubility of trans-cinnamic acid in Benzene, Toluene and Chloroform using the density method.

Procedure

Cinnamic acid was allowed to dissolve into solutions of benzene, toluene and chloroform in a 45C water bath with the purpose of creating saturated solutions. The supernatant from these solutions were removed and placed in a 25C water bath to form a precipitate.

Results

No precipitate formed while the supernatant of each solution was in the 25C water bath and consequently no results were obtained because it was not certain that the solutions were saturated.

Discussion

This experiment was not able to determine any solubilities, because the solutions did not appear to be saturated. Even though there was solute present after the solutions were removed from the 45C water bath, it is believed that the solutions were not saturated due to improper mixing. The cinnamic acid was not mixed into the solvents prior to being placed in the 45C water bath. Consequently, the cinnamic acid stayed packed at the bottom of the test tube for the benzene and toluene solutions and floated on top for the chloroform solution. This may have caused the cinnamic acid to not saturate the solution because it was not mixed into the solvent properly. When this experiment is repeated, the solution will be mixed gently prior to being placed in the 45C water bath.
[Your analysis seems reasonable but check the tubes after 24 hours to rule out the possibility that the solutions were supersaturated. JCB]

Conclusion

No solubilities were determined from this experiment.

Log

2011-11-10

13:36 - Created water bath in 150mL beaker on the hot plate. The initial water temperature was 28C.
13:38 - 0.54g of cinnamic acid was transferred to a 20 mL glass test tube. This tube was labeled tube 1.
13:41 - 0.57g of cinnamic acid was transferred to a test tube. This tube was labeled tube 2.
13:44 - 1.63g of cinnamic acid was transferred to a test tube. This tube was labeled tube 3.
13:50 - 10 mL of benzene was added to tube 1. The tube was capped with a screw cap and sealed with parafilm.
13:53 - 10 mL of toluene was added to tube 2. The tube was capped with a screw cap and sealed with parafilm.
13:56 - 10 mL of chloroform was added to tube 3. The tube was capped with a screw cap and sealed with parafilm.
13:59 - All three tubes were placed in the water bath with a temperature of 43C.
14:17 - All three tubes were removed from the water bath. Undissolved solute was visible in each tube. Final temperature of the water bath was 45C.
14:20 - The supernatant of each tube was transferred to a new tube and each of these new tubes containing the supernatant were capped with a screw cap and sealed with parafilm.
14:28 - Each of the tubes were placed in the 25C water bath.
14:34 - Each tube was sonicated. No precipitate was visible.
14:46 - No precipitate was visible. The experiment was ended.