Linh Bui


Determine the solubility of (trans) - cinnamic acid in methanol using density method. The additivity of volumes is an assumption and the density of (trans) - cinnamic acid is obtained from ChemSpider [remove span tags JCB]


Cinnamic acid was moderately dissolved in methanol at room temperature. Transferred about 2 grams of cinnamic acid and 5 mL of methanol in a test tube. [dissolved would imply that all the solid went into solution - is that accurate? JCB]
Then the mixture was attached to the shake plate and placed in the water bath at 25°C for at least 24 hours [be more specific JCB] [do you mean this? JCB] [is it sufficient to just place the test tube into the bath? JCB]
Transferred 1 mL of the supernatant to a 1 mL volumetric flask.
Weighed the flask and recorded its mass.


The solibility of cinnamic acid in methanol found by using the density method was 1.281 M. [remove span tags JCB]

ONS-EXP 340-Spreadsheet


Previous measurements of the solubility of cinnamic acid in methanol had range from 1.226 M to 1.520 M. The solubility of cinnamic acid in this experiment was 1.281 M. Therefore, the solubility found was likely to lie in the range above. [precise is not an appropriate term here JCB]


The solubility of (trans) - cinnamic acid in methanol is 1.281 M.
[add to solsum sheet JCB]



13:25 - Weighed out 2.0010g of cinnamic acid and transferred to a clean 20 mL test tube.
13:35 - Transferred 5.00 mL of methanol to the test tube containing cinnamic acid.
13:36 - Capped the test tube with a screw cap and sealed it with parafilm.
13:37 - Shook the mixture several times.
13:41 - Observed the mixture: really light yellow liquid on the top and a thick milky white layer at the bottom of the test tube.
13:47 - Attached the sealed test tube to the shake flask apparatus and placed it in the 25°C water bath (vortex at level 3).


10:21 - Weighed and recorded the mass of an empty 1 mL volumetric flask. [was vortex still running? JCB]
10:25 - Filled the flask with 1 mL of methanol.
10:26 - Weighed the flask containing 1 mL of methanol.
10:32 - Weighed that 1 mL volumetric flask again after washing and air drying it.
10:34 - Took the test tube out of the water bath.
10:36 - Transferred 1 mL of the supernatant on the top of the mixture into the 1 mL volumetric flask by using a pipet.
10:39 - Weighed the volumetric flask containing the supernatant.