Starting, Material, serves also as the solvent colorless liquid with a smell of acetic acid Molar Mass: 102. 09 g/mol Melting Point: -73. 1 0C Boiling Point: 139. 8 0C Density: 1. 082g/cm3 Corrosive Flammable and Lachrymator which makes eyes teary. It is poisonous and will cause serious damage if swallowed or inhaled. Phosphoric Acid Catalyst colorless liquid, Molar Mass: 98. 00 g/mol Melting Point: – 42. 35 °C (anhydrous) 29. 32 (hemihydrate) Boiling Point: 158 0C Density: 1. 685g/cm3 Corrosive, Toxic Water Used to destroy acetic anhydride which did not react; precipitates crude aspirin colorless liquid.
Molar Mass: 18. 06 g/mol Melting Point: 0 °C Boiling Point: 100 0C Density: 1. 0g/cm3= Diethyl ether Recrystallization solvent colorless liquid with a sweet, characteristic smell Molar Mass: 74. 12 g/mol Melting Point: – 116°C Boiling Point: 35 0C Density: 0. 7134 g/cm3 Easily ignited, Harmful by ingestion, inhalation or through skin contact. Petroleum Ether Salt out aspirin from the solvent Colorless liquid Molar Mass – Melting Point-40 ? C Boiling Point 36-70 ? C Density – 0. 6475 g/ml The liquid is volatile and very flammable. It presents a high fire risk.
Some formulations may contain chemicals that are suspected carcinogens. Avoid ingestion and inhalation. Acetylsalicylic Acid Product White crystalline powders Molar Mass180. 16 g/mol Melting Point 135 ? C Boiling Point 140 ? C Density 1. 35 g/ml Harmful if swallowed in quantity. Skin, eye and respiratory irritant. May act as an allergen in susceptible people. IV. Data and Results Table 11. 2. Physical Examination of Samples Sample Observations Salicylic Acid Acetic Anhydride 85% Phosphoric Acid Petroleum Ether Diethyl Ether Iodine Solution Table 11. 3. Observation on the preparation of aspirin Actions / Reagents Added.
Observations Salicylic Acid Addition of Acetic Anhydride Addition of 85% Phosphoric Acid Heating under steam bath Addition of cold, distilled water Cooling (Ice bath) Suction Filtration Filtrate Residue Air – dried crystals What is the balanced chemical equation for synthesis of aspirin? Table 11. 4. Percentage yield of actual yield of Aspirin Substance/Reagent/Apparatus Weight (g) Filter paper + Watch glass Filter paper + Watch glass + Crude aspirin Crude Aspirin Theoretical Yield Percentage yield (%): _______ Table 11. 5. Observations on the recrystallization of aspirin Actions / Reagents Added.
Observations Crude Aspirin Addition of diethyl ether Addition of Pet Ether Cooling Filtration Filtrate Residue Dried Crystals Table 11. 6. Percentage Yield Substance/Reagent/Apparatus Weight (g) Filter paper + Watch glass Filter paper + Watch glass + Crude aspirin recrystallized Aspirin Theoretical Yield Percentage yield Table. 11. 7. Melting Point Determination of Crude and Purified Aspirin Addition/ Reagent added Observation Crude aspirin Temp. at which crude aspirin began to melt (0C) Temp. at which crude aspirin finished to melt (0C) Melting Point range of crude aspirin (0C) Purified Aspirin.
Temp. at which purified aspirin began to melt (0C) Temp. at which purified aspirin finished to melt (0C) Melting Point range of purified aspirin (0C) Literature value of melting point range of Apparatus (0C) Table 11. 8. Differentiation of aspirin from starting material Sample Sol’y in H2O FeCl3 test Acidic KMnO4 test Observation (+/-) Observation (+/-) Observation (+/-) Salicylic Acid Acetic Anhydride Acetylsalicylic Acid Table 11. 9. Differentiation of synthesized aspirin and commercially available aspirin Sample Reaction with iodine solution Synthesized Aspirin Commercially Available Aspirin.
V. Sample Calculations 1. ) Theoretical Yield = 2. 0 g salicylic acid ())= 2. 61 g 2. ) Actual Yield = weight of desired product 3. ) Percentage Yield = x 100 VI.
References Groggins, P. H. Unit Processes in Organic Synthesis. 1952. Mc-Graw Hill, Inc. :USA. Eaton, D. C. Laboratory Investigations in Organic Chemistry. 1989. Mc-Graw Hill, Inc. :USA. Timberlake, K. General, Organic, & Biological Chemistry; Structures of life. Platinum Ed. (2004). Pearson Education Inc. 234-238. Matta, M. S. , Staley, D. D. , Waterman, E. L. et. al. , 2003. Pearson Education (Asia) Pte Ltd. : Singapore.
Synthesis of Apirin. (n. d. ). Retrieved September 12, 2012, from http://www. xula. edu/chemistry/department/organic/Notes/24Aspirin. pdf/ Chemistry Experiment: Synthesis of Aspirin. (2003). Retrieved September 12, 2012, from http://www. earlham. edu/~chem/chem111f03/labs/Experiment%2011. pdf/ The Synthesis of Apirin. (n. d. ). Retrieved September 12, 2012, from http://www. reachoutmichigan. org/funexperiments/quick/csustan/aspirin. htm/ Excess and limiting Reagents. (n. d. ). Retrieved September 14, 2012, from http://www. science. uwaterloo. ca/~cchieh/cact/c120/limitn. html.