Matthew McBride


To determine the solubility of trans-cinnamic acid in methanol through the use of the density method .[Link to description of the method as usual JCB]


Cinnamic acid was dissolved in methanol using a 45C water bath to create a saturated solution. The supernatant of this solution was removed and placed in a 25C water bath and a precipitate was allowed to form. The solution was removed from the precipitate and weighed using a 5mL volumetric flask. [Provide very brief procedure JCB]


ONSEXP229-Sheet 1
Using a 5mL volumetric flask, the molarity of a methanol solution saturated with cinnamic acid was found to be 1.274 M
[You didn't use the right solvent density in the spreadsheet and I fixed it (in red) and updated the final result. JCB]


Previous experiments have found the solubility of cinnamic acid in methanol to range from 1.2-1.38 M with a mean of 1.31 M. The 1.274 M found in this experiment showed excellent agreement.


The density method found that the solubility of cinnamic acid in methanol was 1.274 M at 24C.



13:08 - Created water bath in 150mL beaker on the hot plate. Initial water temperature was 30C.
13:11 - 4.9g of cinnamic acid was transfered to a 20mL glass test tube. Approximately 11mL of methanol was added to the tube.
13:51 - Test tube was capped with a screw cap and placed in the water bath at a temperature of 45C.
13:53 - Cinnamic acid was observed going into the solution.
13:55 - Water bath was at a temperature of 44C.
13:59 - Water bath was at a temperature of 42C.
14:08 - Test tube was removed from the water bath and the supernatant was poured into another 20mL test tube. The tube with supernatant was capped with a screw cap, sealed with parafilm, [and parafilm? JCB] and placed in a 25C water bath.
14:11 - Precipitation from the solution was visible.
14:14 - Water bath was at a temperature of 24C.
14:19 - Measured mass of empty 5mL flask on the scale.
14:26 - Measured mass of 5mL flask filled with methanol.
14:31 - Flask was dried by rinsing with acetone [How? JCB] and the mass of the empty 5mL flask was obtained.
14:39 - Final temperature of the water bath was 24C. Transferred the supernatant from the precipitate to the 5mL volumetric flask. Measured the mass of the 5mL flask containing the supernatant.