[remove span tags JCB]
Researchers
Lizzie Clark with Andrew Lang

Objective
To recrystallize cinnamic acid using pure ethanol.

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

Procedure
1. Weigh empty volumetric flask (in grams).
2. Weigh volumetric flask with 25mL of pure ethanol (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 pure ethanol.
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 2.0M solution [cannot access JCB]
Planning Sheet for 3.0M solution [cannot access JCB]

Results


Log
3/27/12
*Flask A= 2.0M solution, Flask B= 3.0M solution
*Room temperature at 21.5 C
9:31- Empty flask A weighed 78.174g. Empty Flask B weighed 78.640g.
9:34- Measured out 9.716g exactly of cinnamic acid and poured into erlynmeyer Flask A. Measured our 17.264g of cinnamic acid and poured into erlynmeyer Flask B.
9:50- Poured 25mL of pure ethanol into each flask and stoppered.
9:55- Placed both flasks into warm water bath at 61 C, stirring occasionally till solute completely dissolved.
9:59- Flask A completely dissolved. Bath temperature at 73 C. Placed aside to cool at room temperature.
10:03- Flask B completely dissolved. Bath temperature at 69 C. Placed aside to cool at room temperature.
[did any precipitate form? JCB]