EXP241

= Researchers = Lizzie Clark with Lacey Condron and Samantha Gaines = Objective = To calculate the solubility of trans-cinnamic acid in 2-butanol using the density method. = Materials = 25 mL volumetric flask 2-Butanol Electronic Balance Hot Water Bath Thermometer Trans-Cinnamic Acid Parafilm Weigh Paper Chemical Spatula (to measure out solute) 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 2-butanol into the volumetric flask. 6. Using the electronic balance, measure and record the weight of the filled volumetric flask and 2-butanol. 7. Calculate the predicted amount of trans-cinnamic acid needed for saturation of 30mL of 2-butanol, plus 33% more than that. Measure out this amount of trans-cinnamic acid using the electron balance. Record weight. 8. Pour approximately 30mL of 2-butanol into a 100mL beaker. 9. Add measured amount of trans-cinnmic acid to the 2-butanol 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). 12. Weigh empty 25mL volumetric flask (to assure that it is the original one used or to obtain the new weight). 13. Pipette 25mL of the saturated 2-butanol + trans-cinnamic acid solution into ‍flask and weigh. = Results = Measured solubility of trans-cinnamic acid in 2-butanol = Discussion = As of 11/28/11, the observed solubility of 0.8919744071100M has never before been tested. This value is comparable to the predicted value of 0.663 M (2011-12-05) especially since this measurement was performed at a higher temperature than other alcoholic solvents for this solute. = Conclusion = Observed solubility of trans-cinnamic acid in 2-butanol was 0.8920M.

Log
2011-11-28 9:10- Weighed empty 25mL volumetric flask to be 20.2436g. 9:13- Weighed 25mL volumetric flask filled with 25mL of 2-butanol to be 40.4086g and then parafilmed. 9:30- Measured out 5.1665g of cinnamic acid (calculated saturation plus 33%). Room temperature taken at 19.9C in balance room. 9:31- Added 5.1665g of trans-cinnamic acid and 30mL of 2-butanol to a 100mL beaker. 9:33- Room temperature in lab taken at 19.0C. 9:35- Placed beaker in 45.0C warm water bath. 9:37- Added more hot water to bath to get temperature back up to 45C. 9:39 -All solute dissolved, place in 26C cool water bath. 10:08- No precipitate, swirled and removed parafilm. 10:40- Precipitate formed. Water temperature at 24.3C. 10:45- Reweighed the empty 25mL volumetric flask to ensure it was the original (weighed 20.2463g-it is the same flask). 10:51- Bath has cooled to 23.8C. 10:55- Decanted 25mL of the saturated trans-cinnamic acid and 2-butanol solution into the 25mL volumetric flask. 11:07- Temperature taken at 19.0C in balance room. Weighed volumetric flask with solution to be 41.4494g. Note: Many More crystals formed during transport from the lab to the second weighing in the balance room.