EXP268

=Researcher= Stephanie Costa

=Objective=

To determine the solubility of [|cinnamic acid] in [|ethylene glycol] at 25C. The additivity of the volumes is [|assumptive].

=Procedure=

The solubility of cinnamic acid in ethylene glycol at room temperature was tested by dissolving the cinnamic acid into ethylene glycol with a 50-56.5C hot water bath. The supernatant of cinnamic acid and ethylene glycol was poured off while the test tube was still hot. The supernatant was used for the remainder of the experiment. The solution was cooled to room temperature (19C). The solubility was found using the density method.

=Results= [|Calculations sheet] [|Density sheet]

The results were inconclusive because the densities of cinnamic acid and ethylene glycol were to similar. The density method can not be used for this experiment. An NMR needs to be performed.

=Discussion=

Due to the densities of the solute and solvent being very similar, the density method can not be used. Therefore, the solubility was not found in this experiment. A follow up experiment (EXP270) will take the NMR of the solution.

=Conclusion= This experiment was inconclusive because the densities of the solute and solvent were too similar.

=Log=

2012-03-7
11:18- the hot plate was turned on and set to #4. The hot water bath was 23C 11:21- 4.0928g cinnamic acid was added to a 20mL test tube. 11:22- the hot water bath was 29C 11:27- the hot water baht was 40C 11:36- ethylene glycol was added to the 15mL mark on the test tube 11:38- the tube was inverted multiple times, only about 10 mL were added initially to the test tube. Parafilm was added around the lid. 11:42- the hot water bath was adjusted to #1 11:44- the hot water bath was 50C. the test tube was placed in the hot water bath 11:45- the hot water bath was 51C. solute was seen in the test tube 11:49- the hot water bath was 52C. solute was seen. Test tube was inverted five times 11:51- the mass of the empty of a 2mL volumetric flask was found to be 18.2072g. 11:52- the hot water bath was 53C. solute was seen. 11:54- the mass of ethylene glycol and volumetric flask was found to be 20.4259g. 11:56- the hot water bath was 54C. solute was seen in the test tube. the test tube was inverted five times 11:59- the room temperature bath was 43C 12:03- about 5mL of ethylene glycol was added to the sample and parafilm was replaced around the cap. The test tube was inverted. 12:05- the empty 2mL volumetric flask was cleaned, dried and its mass was found to be 18.2086g. 12:06- the hot water bath was 54C. solute was seen in the test tube. the tube was inverted 12:07- the room temperature baht was 41.5C 12:08- the hot water bath was 55C. solute was seen and the tube was inverted 12:14- the hot water bath was 55C. solute was seen and the tube was inverted 12:15- the room temperature bath was 40C 12:19- the hot water baht was 56C. solute was seen in the test tube. about 2-3mL of solvent was added. Parafilm was replaced around the cap and the tube was inverted. 12:24- the room temperature bath was 37C, and was discarded. a second room temperature bath was started. The temperature of the second room temperature bath was 25C. 12:29- the hot water bath was 56C. the solute was still seen. 12:36- the hot water bath was 56.5C. solute was seen. The hot plate was turned off. 12:43- the supernatant was poured off and filtered into a clean 20mL test tube. parafilm was placed around the cap and it was placed into the room temperature bath. The room temperature bath was 24C.

2012-3-12
11:19- the room temperature bath was 19C. the empty 2mL volumetric flask was weighed and found to have a mass of 18.2081g. Precipitate was seen in the sample. 11:30- the mass of the solution in the 2mL volumetric flask was 20.4245g