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