Lizzie Clark with Andrew Lang

To recrystallize cinnamic acid using distilled water.

Trans-cinnamic acid (MSDS)
125 mL erlynmeyer flask
Stopper for erlynmeyer flask
Weigh Paper
Electronic Balance
Chemical Spatula
25 mL volumetric flask
25 mL distilled water (MSDS)
Hot water bath
Cool water bath
Safety Goggles
Lab Coat
Vacuum hose
Ring Stand and clamp
Buchner funnel
Rubber filter column
Filter paper
Side arm flask
Plastic Spatula

1. Weigh empty volumetric flask (in grams).
2. Weigh volumetric flask with 25mL of distilled water (solvent) in it.
3. Pour the 25mL of solvent into an erlynmeyer flask and place stopper on the top to prevent evaporation of solvent.
4. Calculate and measure out the amount of trans-cinnamic acid (solute) needed for the intended concentration.
5. Add measured trans-cinnamic acid to erlynmeyer flask with distilled water.
6. Place erlynmeyer flask in hot water bath and swirl periodically.
7. Gradually increase the water bath's temperature until all solute has dissolved.
8. Record temperature that the solute finally dissolves at.
9. Place flask aside to cool at room temperature.
Planning Sheet for 0.25M solution
Planning Sheet for 0.1M solution
Planning Sheet for 0.05M solution
Planning Sheet for 0.01M solution

We got an 80.6% return from Flask A (0.05M solution).

*Working toward a concentration of 0.25 M.
9:33- Empty 25mL flesk weighed 20.247g.
9:36- 25mL of distilled water in flask weighed to be 45.208g.
*Room temperature at 19.0 C.
9:51- Measured out experimental amount of cinnamic acid of .955g (the predicted value was 0.954g).
9:58- Added 25mL of distilled water to beaker and added measured cinnamic acid. Parafilmed beaker.
9:59- Place in hot water bath at 49.0 C and swirled.
10:04- Hot water bath at 53.5 C. Stopped swirling and left to sit in hot water bath while my lab partner got close to her boiling point (of around 69.0 C) because the boiling point for water is much higher.
* Dr. Andrew Lang later brought solution to a boiling but all the solute still did not dissolve.

* Restarted experiment with a new concentration of .0.1 M. This new concentration required a new value of cinnamic acid of 0.375g.
9:03- Funneled and pipetted 25mL of distilled water into volumetric flask.
9:07- Measured out 0.374g of cinnamic acid on the electric balance using weigh paper.
9:08- Poured the 25mL distilled water and 0.374g of cinnamic acid into a 125mL erlynmeyer flask and placed a stopper on the top.
9:09- Placed in 52.0 C hot water bath and swirled periodically.
9:11- Hot water bath temperature at 54.0 C.
9:32- Hot water bath temperature at 58.8 C.
9:37- Hot water bath temperature at 61.0 C.
10:00- Hot water bath temperature now at 65.0 C.
10:10- Hot water bath temperature now at 79.0 C.
10:14- Hot water bath temperature now at 82.0 C.
10:20- Hot water bath temperature now at 86.0 C.
10:29- Hot water bath temperature now at 88.0 C.
* No changed detected. Forced to abandon due to time constraints.

*Further altered experiment and worked with multiple flasks. Flask A represents a 0.05M solution, and Flask B represents a 0.01M solution.
*Room temperature at 20 C
Flask A:
8:55- Empty volumetric flask weighed 20.248g.
8:58- 25mL of distilled water in volumetric flask weighed 45.169g.
8:59- Poured 25mL of distilled water into erlynmeyer flask (Flask A) and stoppered.
9:06- Measured out 0.186g of cinnamic acid and placed in Flask A.
9:08- Placed Flask A in hot water bath at 73 C (which rose to just under 100 C throughout the course of the experiment). Swirled periodically till all solute dissolved.
*Be aware that the stopper may pop off with force during the heating process. Wear proper safety gear.
9:19- Water bath at 80 C.
9:32- Temperature remained constant, so placed Flask A directly on hot plate.
9:34- Water in Flask A brought to nearly boiling.
9:35- All dissolved in Flask A. Set aside to coll at room temperature.
Flask B:
9:01- Empty volumetric flask weighed 20.375g.
9:02- 25mL of distilled water in volumetric flask weighed 45.189g.
9:03- Poured 25mL of distilled water in erlynmeyer flask (Flask B) and stoppered.
9:11- Measured out 0.038g of cinnamic acid and added it to Flask B.
9:13- Placed Flask B in hot water bath, now at 75 C.
9:19- Water bath at 80 C.
9:21- Flask B completed dissolved at 81 C. removed Flask B to cool at room temperature.

Filtration of Flask A (0.05M solution)
9:40- Set up vacuum filtration system similar to what is seen here. Ran vacuum for ~30 mins.
10:35- Weight of the filtrate is 0.15g.
10:35- Filtrate placed at room temp to see if more drying is needed.
10:40- Weight of the filtrate remained the same, filtration is complete.
*Flask B will not be filtrated because we are interested in using the highest molarity possible- which was Flask A.