EXP282

Lizzie Clark with Andrew Lang
 * Researchers**

To recrystallize cinnamic acid using ethanol and water in a 50/50 volume. Trans-cinnamic acid (MSDS) 125 mL erlynmeyer flask Stopper for erlynmeyer flask Weigh Paper Electronic Balance Chemical Spatula Funnel Pipette 25 mL volumetric flask 12.5 mL pure ethanol (MSDS) 12.5 mL distilled water (MSDS) Hot water bath Cool water bath Thermometer Safety Goggles Lab Coat Vacuum Hose Gloves Ring Stand and clamp Buchner funnel Rubber filter column Filter paper Side arm flask Plastic spatula
 * Objective**
 * Materials**

1. Weigh empty volumetric flask (in grams). 2. Weigh volumetric flask with 25mL of pure ethanol and distilled water 50/50 volume combination (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 the solvent mixture. 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.
 * Procedure**

[|Planning Sheet for 0.5M solution.] Planning Sheet for 1M solution.
 * Results**
 * [Cannot access google doc - RA]**
 * [Calculated yield to be 77.8% based on log data of 3.271g recovered from initial 4.203g - RA]**


 * Log**

4/17/12
Flask A: 1.0M solution- 4.203g of cinnamic acid needed Flask B: 0.5M solution- 1.969g of cinnamic acid needed 9:35- Measured out 25 mL of water/ethanol (50/50 volume) and poured into flask A. 9:37- Measured out 25 mL of water/ethanol (50/50 volume) and poured into flask B. 9:42- Measured 4.202g of cinnamic acid and added to flask A. 9:48- Measured 1.968g of cinnamic acid and added to flask B. 9:51- Stoppered flasks and placed in warm water bath starting at 27.8 C. 9:57- Water temperature at 51 C. 9:58- Solute in flask B completely dissolved. Placed aside to cool. 10:01- Water temperature at 60 C. 10:02- Water temperature at 61 C. Flask A solute completely dissolved. 10:03- Placed flask A aside to cool.
 * Room temperature at 20.5 C

4/24/12 9:25- Added 1.0M (flask A) solution to vacuum __#|filtration system__. 9:35- Checked crystals and broke up chunks with plastic spatula. 9:55- Removed filtrate and weighed to be 4.220g. 10:05- Replaced solute on filter system. 10:19- Weighed filtrate to be 3.387g. 10:20- Left contents on scale. 10:23- Contents weighed 3.379g. 10:24- Replaced contents on vacuum filtration system. 10:30- Reweighed filtrate to be 3.317g. 10:31- Replaced contents on vacuum __#|filtration system__. 10:39- Reweighed filtrate to be 3.274g. Lizzie had to leave. 11:00 - Reweighed filtrate to be 3.271g. 11:15 - Reweighed filtrate to be 3.271g. Filtrate assumed to be dry - experiment end.
 * Room temperature at 21 C.