EXP223

=Researchers= Samantha Gaines with Lacey Condron and Lizzie Clark.

=Objective= To calculate the solubility of trans-cinnamic acid in 1-butanol by density method. The additivity of volumes is an assumptionand the density of the solid is obtained from ChemSpider.

=Materials= electronic balance hot water bath test tube rack 25 mL volumetric flask beaker pipette funnel microspatula trans-cinnamic acid 1-butanol

=Procedure= Weigh 1-butanol solution in volumetric flask at room temperature. Record mass and volume. Decant solution from volumetric flask into beaker. Add cinnamic acid until until it no longer dissolves into the solution at room temperature. Heat the solution in a hot water bath from 35 to 40 degrees Celcius until cinnamic acid is dissolved. Alternate between adding cinnamic acid and heating solution in water bath until cinnamic acid does not dissolve into the heated solution. This is a saturated solution. Let solution cool to room temperature. Precipitate should form as solution cools. When completely cooled, pipette supernatent into volumetric flask. Weigh on electronic balance at room temperature. Record mass and volume. Calculate density of butanol and density of butanol solution saturated with cinnamic acid. Enter all data into "results" spreadsheet.

=Results= Measured solubility of trans-cinnamic acid in 1-butanol. =Discussion= The observed density of 1-butanol was 0.805996 g/mL. The observed density of 1-butanol saturated with trans-cinnamic acid was 0.838932 g/mL. From this the concentration of trans-cinnamic acid in the saturated solution was calculated to be 0.62904141830666 M. Previous measurements for the solubility trans-cinnamic acid in 1-butanol average to be 0.714 M with a standard deviation of 0.242 M. The measurement obtained from this experiment is well within the standard deviation. =Conclusion= The solubility of trans-cinnamic acid in 1-butanol was measured to be approximately 0.629 M. =Log=

2011-10-03
9:37 - Weighed 25 mL volumetric flask with electronic balance accurate to .0001 g at room temperature (20.4 degrees C). Empty flask weighed 20.3202 g. 9:45 - Weighed 25 mL of 1-butanol in volumetric flask with electronic balance. Butanol weighed 20.1499 g. 10:02 - Decanted butanol into beaker and added excess butanol (approximately 2 mL). 10:04 - Began adding trans-cinnamic acid with microspatula. 10:19 - Beaker placed on test tube rack in hot water bath at 36 degrees C for 3 minutes to dissolve cinnamic acid. 10:23 - Added cinnamic acid and put beaker back into water bath at 36 degrees C for 6 minutes. 10:31 - Beaker removed from water bath and let cool. 10:35 - Cool solution had no precipitate. More cinnamic acid was added. 10:38 - Beaker placed in water bath at 37 degrees C for 10 minutes (water bath had heated to 38 degrees C by the time the beaker was removed.) 10:49 - More cinnamic acid added to solution. 10:52 - Beaker placed in water bath at 39 degrees C for 5 minutes. 10:58 - Beaker removed and let cool. 11:00 - Beaker was parafilmed. 12:19 - No precipitate had formed, added more cinnamic acid and swirled. 12:25 - Not all solute dissolved. Placed beaker in water bath 42C 12:29 - Swilred - all solute dissolved. 12:30 - Added more solute and swirled. All solute dissolved. 12:32 - Added more solute and swirled. Not all solute dissolved. Placed beaker in water bath 42C. 12:32 - Swirled. Not all solute dissolved. Placed beaker in water bath 42C 12:41 - Swilred. All solute dissolved, clear/yellow solution. Placed beaker on bench to cool. 12:42 - Parafilmed beaker. exact time not recorded - Washed volumetric flasks with alconox and rinsed with distilled water. Flasks were allowed to air dry.

2011-10-5
exact time not recorded - Crystals were observed in beaker indicating a saturated solution. 12:24 - Weighed empty volumetric flask at 20.5 degrees C with electronic balance. Flask weighed 20.3092g. 12:26 - Pipetted 25 mL of supernant into volumetric flask. 12:33 - Weighed 25 mL of supernatent. Solution and flask weighed 41.2825 g.