Researchers

Lacey Condron with Lizzie Clark and Andrew Lang

Objective

To recrystallize cinnamic acid using hexane.

Procedure

Hexane was obtained, volumetric flask was weighed (20.267 g) and the weight of 25 ml of hexane (16.622 g) was obtained from the electronic balance. Contents of the flask were transferred to a 100 mL beaker. The amount of cinnamic acid was previously calculated to make a 0.25 M using the Planning Sheet. Cinnamic acid (0.954 g) was weighed and added to the beaker; this procedure was done in a room with a measured temperature at 19.0 degrees C. After the cinnamic acid was added, the beaker was covered with parafilm to avoid spilling, contamination and vaporization of the liquid.The beaker was placed in a hot water bath (tap water) at 55 degrees C to allow the solute to fully dissolve.The beaker was swirled periodically to assist in dissolving the solute. The hot water bath was heated to approximately 60 degrees C and the solute was still not fully dissolved. After about 20 minutes, the experiment was abandoned because it would not dissolve. The volumetric flask was weighed (20.322 g) and the weight of 25 mL of hexane (16.628 g) was obtained from the electronic balance. Contents of the flask were placed in an Erlenmeyer flask with a stopper because the hexane's high volatility caused the parafilm to be disintegrated and result in vaporization of hexane. The amount of cinnamic acid was cut in half, to attempt to get a 0.125 M solution. The cinnamic acid (0.476 g) was weighed and added to the Erlenmeyer flask. The Erlenmeyer flask was placed in a 65 degree water bath and was swirled periodically to assist in dissolving the solute. After sitting in the water bath for 15 minutes the solute was still not dissolved. Because hexane has a boiling point of 67 degrees C, the solvent should have dissolved already.

Part 2: Hexane was obtained, volumetric flask was weighed (20.268 g) and the weight of hexane (16.622 g) was obtained from the electronic balance. Contents of the flask was transferred to 250 mL Erlenmeyer flask with stopper. The amount of cinnamic acid was previously calculated to make a 0.1 M solution using the. Cinnamic acid (0.375 g) was weighed and added to the beaker; this procedure was done in a room with a measured temperature of 21.0 degrees C. After the cinnamic acid was added, a stopper was used to avoid spilling, contamination, or vaporization of the liquid. The flask was placed in a hot water bath (tap water) at 53 degrees C to allow the solute to fully dissolve. The temperature was steadily rising until it reached near the boiling point of hexane, which is 67 degrees C. The beaker was swirled periodically to assist in dissolving the solvent. The solvent reached 67 degrees C over a period of 30 minutes and the solvent still wasn't fully dissolved. Experiment abandoned. Before disposing of the experiment, it was allowed time to cool before disposing of the chemicals. While it cooled crystals formed in the flask alongside the undissolved solvent.While cooling, the top became loose and allowed the solvent to evaporate.

Results

This experiment resulted in 0.954 g and 0.375 g of Cinnamic acid created a supersaturated solution that Hexane could not fully dissolve to make a 0.05 M solution.


Log

9:36 Weighed 25mL volumetric flask- (20.267 g)
9:39 Pipetted 25mL of hexane into the previously weighed volumetric flask. Weighed 25mL of hexane- (16.622 g)
9:42 Poured the previously weighed 25mL of hexane into 100mL beaker. Covered with parafilm.
9:54 Weighed/ added cinnamic acid (0.954 g) at 19.0 degrees C.
9:57 Placed beaker in 50-55 degree C water bath using tap water.
10:15 Beakers were continuously swirled to assist in the dissolving process while the temperature of the water bath was maintained to stay within 50-55 degrees C.
10:15 Solute was not dissolved, experiment abandoned.
10:16 Weighed of 25mL volumetric flask- (20.322 g)
10:17 Pipetted 25mL of hexane into the previously weighed volumetric flask. Weighed 25mL of hexane- (16.628 g)
10:19 Poured the previously weighed 25mL of hexane into Erlenmeyer flask with stopper.
10:22 Weighed/ added cinnamic acid (0.476 g) at 19.0 degrees C.
10:24 Placed beaker in 60 degree C water bath using tap water.
10:25 Beakers were continuously swirled to assist in the dissolving process while the temperature of the water bath was maintained to stay within 60-65 degrees C.
10:40 Solute was still not dissolved, experiment abandoned.

Part 2:
9:07 Weighed 25 mL volumetric flask- (20.268 g)
9:08 Pipetted 25 mL of hexane into the previously weighed volumetric flask. Weighed 25 mL of hexane- (16.622 g)
9:11 Poured the previously weighed 25 mL of hexane into 250 mL Erlenmeyer flask. Placed stopper on flask.
9:12 Weighed/ added cinnamic acid (0.375 g) at 21.0 degrees C.
9:14 Placed beaker in 53 degree C water bath using tap water.
9:15 Beakers were continually swirled to assist in the dissolving process while the temperature of the water bath was rising steadily to reach the boiling point of hexane, 67 degrees C.
10:04 The temperature reached 67 degrees C and the solvent was still not fully dissolved, experiment abandoned.