Researcher

Rida Atif

Objective

To determine the solubility of cinnamic acid in boiling n-hexane to confirm results of EXP283

Procedure

A gram of trans-cinnamic acid was put into an Erlenmeyer flask along with 20mL of n-hexane and heated on a hot plate until boiling. Another Erlenmeyer flask with just 20mL of n-hexane was also heated until boiling on hot plate. The contents of each of the flasks were transferred to a 1mL volumetric flask and then weighed.

Results

Calculation sheet
The concentration of the cinnamic acid in the hexane was calculated to be 0.1863M

Discussion

Since this experiment was done to confirm the results of EXP283 it proved that something certainly went array in the former experiment. In this experiment the density of the hexane is more aligned to what predictions and previous calculations say.
We found the density of boiling hexane to be 0.646 g/mL experimentally.
It is also believed that a small impurity was in the cinnamic acid that was difficult to dissolve which caused more of the solvent to be added in to the flask than needed. Because of the large amount of hexane that went into the flask, the solubility was calculated to be 0.06M from the boiling hexane which is unrealistically low because the predicted solubility of 0.5M from the solubility curve was a lot higher.

Conclusion

The solubility of the cinnamic acid in the hexane was calculated to be 0.18M which would mean that the predicted recovery yield of the cinnamic acid would be approximately 85%. This makes more sense since the yield was 64% in EXP281

Log

2012-30-04

11:57 - Turned on hot plate to 200C.
12:13 - Added 1.0033 g of trans-cinnamic acid into Erlenmeyer flask.
12:14 - Added approximately 20mL of hexane into Erlenmeyer flask and set on hot plate
12:15 - Added approximately 20mL of hexane into another Erlenmeyer flask and set on hot plate.
12:17 - Weight of empty 1mL volumetric flask with cap 20.4309g
12:22 - Triturated pipet to make warm to prevent any crystallization during transferring.
12:23 - Transferred boiling hexane with cinnamic acid from Erlenmeyer flask into 1mL volumetric flask 21.0904g.
12:29 - weight of empty 1mL volumetric after being cleaned and dried properly 20.4317g
12:37 - Triturated pipet to make it warm to prevent any crystallization during transferring.
12:38 - Transferred vboiling hexane into 1mL volumetric flask 21.0779g