EXP232

Researchers
Lizzie Clark and Lacey Condron

Objective
To measure the solubility of trans-cinnamic acid in propyl acetate using the density method.

Materials
25 mL volumetric flask Propyl Acetate Electronic Balance Hot Water Bath Thermometer Trans-Cinnamic Acid Lab Coat Gloves Goggles

Procedure
1. Put on safety gear including goggles, lab coat, and gloves. 2. Gather the materials listed above. 3. Measure and record the temperature of the balance room (preferably in Celcius to make later calculations easier). 4. Using the electron balance, weigh and record the empty 25 mL volumetric flask (g). 5. Carefully pour 25 mL of propyl acetate into the volumetric flask. 6. Using the electronic balance, measure and record the weight of the filled volumetric flask and propyl acetate. 7. Calculate the predicted amount of trans-cinnamic acid needed for saturation of 30mL of propyl acetate, plus 33% more than that. Measure out this amount of trans-cinnamic acid using the electron balance. Record weight. 8. Pour approximately 30mL of propyl acetate into a 100mL beaker. 9. Add measured amount of trans-cinnmic acid to the propyl acetate in the beaker, swirl, and parafilm. 10. Measure and record the temperature of the laboratory area (in Celsius). 11. Place beaker in warm water bath of around 45C and observe until crystals form (indicating that the solution is saturated). 10. Weigh empty 25mL volumetric flask (to assure that it is the original one used or to obtain the new weight). 11. Pipette 25mL of the saturated propyl acetate + trans-cinnamic acid solution into ‍flask and weigh. Planning Sheet

Results
The solubility of cinnamic acid in propyl acetate at 25.5 C is 0.61878463833606 M. Calculation spreadsheet.

Discussion
The observed solubility of trans-cinnamic acid in propyl acetate of 0.61878463833606 M at 25.5 C has never before been calculated.

Log
9:00- Empty volumettric flask weighed 20.0403g. 9:05-25 mL of propyl acetate + 25mL volumetric flask weighed 42.1404g. 9:07- Poured 25mL of propyl acetate into 100 mL beaker and filled beaker to 32mL with propyl acetate from bottle and covered with parafilm. 9:25- Meaured out the predicted 5.31g of trans-cinnamic acid and weighed to be exactly 5.3169g. 9:26- Room temperature meaured at 20.9 C 9:27- Added the 5.3169g of cinnamic acid to the 32mL of propyl acetate and parafilmed. 9:42- Placed solution in 45 C water bath filled with tap water. 9:47- Water had cooled to 40 C. Replaced water to refresh 45 C temperature. 9:48- Swirled solution, not all solute dissolved, placed back in bath. 9:50-Replaced water to refresh 45 C temperature. 9:55- Swirled, not all solute dissolved, placed back in bath. 10:00- Replaced water to refresh 45 C temperature. 10:05- Swirled. All solute dissolved. Replaced in water bath at 26 C. Turned down dial on water bath temperature to slowly cool solution. 10:15- Noticed crystals forming. 10:50- Weighed empty original volumetric flask with a stopper to be 22.6237g. 11:05- Pipetted 25mL of supernatant, beaker still in water bath at 25.5 C, into the volumetric flask and put on stopper. 11:18- Weighed 25mL of propyl acetate supernatant in flask to be 45.3905g.
 * Note: The solution had a light yellow color.