Researcher


Stephanie Costa

Objective


To determine the solubility of cinnamic acid in nitromethane at 25C. The additivity of the volumes is assumptive .

Procedure


The solubility of cinnamic acid in nitromethane at room temperature was tested by dissolving the cinnamic acid into nitromethane with a 31-34C hot water bath. The solution was cooled to room temperature (24C), then to 7C as an ice bath. The solubility was found using the density method.

Results

Calculations sheet
Density Sheet

The solubility according to the density sheet is 1.4923M. This is not a valid value.

Discussion


Solvent Predictor
Here is the value I based my experiment on.
(Complete Solvent Predictor for cinnamic acid)

Abraham Solvents Model
This link also discusses nitromethane as an outlier.

The data obtained from this experiment was calculated to a 1.4923M. This is not a valid result due to the pure mass of nitromethane and the solution of cinnamic acid is too similar. The two masses differ by only 0.0106g.

There were problems with this experiment. The supernatant of the solution was not poured off before placing the test tube into the room temperature bath. However, the solution was supersaturated because of the crystal formation in the test tube. The temperature of the bath was also not room temperature or an ice bath.

Conclusion


The test was inconclusive because the density method can not be used. The mass of the pure solvent and solution were too close together.

Log

2012-1-23

11:58- 1 ml volumetric flask was cleaned and dried.
12:05- 0.3663g of cinnamic acid was weighed out and placed in a test tube.
12:11- a room temperature bath was started. the room temperature bath was 20C.
12:18- the hot plate was turned on to 100C. a 500mL beakers filled with 400mL of water was placed on the hot plate. the temperature was 25C.
12:19- the room temperature bath was 22C. the room temperature bath was adjusted with some warm water.
12:22- the hot water bath was 25C. the room temperature bath was 23C.
12:23- the hot water bath was 27C. the room temperature bath was 23.5C the room temperature bath was adjusted with warm water.
12:26- the hot water bath was 28C. the room temperature bath was 24.5C.
12:28- the hot water bath was 29C. the room temperature bath was 24.5C. the room temperature bath was adjusted with warm water.
12:31- the hot water bath was 30C. the room temperature bath was 24.5C.
12:36- nitromethane was added to the 3/4th mark on the test tube.
12:38- parafilm was added around the lid and the test tube was inverted twice.
12:39- the hot water bath was 31C. the room temperature bath was 24C. the test tube was added to the hot water bath.
12:40- the room temperature bath was adjusted with warm water.
12:41- the hot water bath was 33C. Solute was visible. the room temperature bath was 25C.
12:42- the empty volumetric flask was weighed and found to have the mass of 42.8265g.
12:46- the hot water bath was 33C. Solute was visible. the test tube was inverted twice and replaced into the hot water bath. the room temperature bath was 25C.
12:48- the room temperature bath was 25C. the hot water bath was 33C. solute was visible, the test tube was inverted twice and replaced into the hot water bath.
12:49- the 1 mL volumetric flask with nitromethane was weighed and found to have a mass of 43.9537g.
12:53- the hot water bath was 34C. solute was still seen. the test tube was inverted twice and replaced into the hot water bath. The room temeprature bath was 24.5C. the room temperature bath was adjusted with warm water.
12:55- the hot plate was turned off.
13:31- the test tube was placed in the room temperature bath (24C).
13:35- the 1 mL volumetric flask was weighed and found to have a mass of 42.8265g.
13:39- the room temperature bath was 24C.
13:45- the room temperature bath was 24C.
14:53- ice was added to the room temperature bath. the now ice bath was 7C.

2012-1-25

12:17- the ice bath was 17C. crystals were seen in the sample. the empty flask was reweighed and found to have a mass of 42.8265g.
12:20- the solution's density was measured in the 1 mL volumetric flask and found to be 43.9643g.