Organic Chemistry 333L, section 03M LaboratoryPost-LabSynthesis ofPhthalic acidSynthesized by Cameron Kahn14 January 2019TA: James Collie1 | P a g eResults:Observations:Phthalic acid is a white crystalline precipitate. While doing the experiment there were no visible signs of impurities. The recrystallized crystals looked long, clear, and shard-like white stained glass. Data:- Initial mass of phthalic acid: 0.10grams- Recrystallized mass of phthalic acid: 0.075grams- Melting Point of recrystallized product: 209°C- Percent Recovery (mass): 75.0%- Percent Difference (temperature): 9.1% Calculations:Percent Recovery=Amount Pure SolidAmount Impure Solid× 100 ¿0.075 gram0.10 gram×100 ¿75.0 % Percent Difference=|Treference−Tsample|Treference× 100 ¿|230℃ −209 ℃|230℃× 100 ↑=9.10 % (temperature)Conclusions:Recrystallization is a fast and convenient method for purification of a substance. The basic process behind recrystallization is to dissolving the substance in a liquid, apply heat until solution reaches its melting point, and then cool the solution. Upon recrystallization of the crude sample of phthalic acid, about 75% of pure phthalic acid remained after the removal of all soluble and insoluble purities. The melting point obtained in the experiment was measured to be 209°C. The actual melting point for phthalic acid is measured to be 230°C. The measured percentdifference in temperature is calculated to be 9.1%. Comparing the experimental to the actual melting point, one can only hypothesis that there were still impurities present within the “recrystallized pure” product. This is due to a human error involving the suction filtration systemand not appropriately filtering the recrystallized sample. This would explain why the 2 | P a g ePercent yield: mass of recrystallized sample x 100 mass of crude sample = .075grams (recrystallized) x 100 = 75% yield .10grams (crude)***percent yield and percent recovery are used interchangeably and both calculations are done in the same fashion however; the correct usage for the experiment on recrystallization would be to use percent recovery.experimental melting point was measured to have a lower temperature than the actual melting point (melting point depression). The lessons learned in the experiment: 1. How to use the equipment properly. 2. How to find the mass and temperature of a sample. 3. Percentage recovered (mass). 4. Percentage difference in temperature.5. Identification of a sample based on physical properties such as melting point.3 | P a g