Organic Synthesis of Aspirin Chemistry Formal Lab Essay Example

sulfuric acid (HASPS), an acid catalyst: (Diagram from 1) The impurities left over (unrelated salicylic acid, acetic acid and sulfuric acid) are removed by the process of rationalizations.

This process separates pure aspirin by precipitating it out of the impure solution. Most of the digestive system without causing burns. 2 Ultimately, ecstatically acid hydrolysis with water, mainly in the bloodstream, to regenerate salicylic acid: (Diagram from 1) There are four mathematical calculations given by the instructor. They are: 1.

Density = Mass / Volume 2. # of moles of the limiting reagent = Weight of the limiting reagent (grams) / Molecular weight limiting reagent (grams/mole) 3.

Theoretical Yield = # of moles of limiting reagent X Of supersonically weight of aspirin (Ecstatically Acid) 4. Percent actual Yield = (Actual yield / Theoretical Yield) X 100% Experimental Chemicals Used: *salicylic Rid: *Acetic Anhydride: *Sulfuric Acid: Con. HASPS(l)(Provided) *Acetic Acid:CHICHI(l)(Prepared) *Ecstatically Acid:CHICHI(S)(Prepared) Procedures: Followed the procedures listed in the University of Winnipeg, Department of

Chemistry Laboratory Manual, page 43. Results Data: Prearrangement's Method of Determination Volume of acetic anhydride. O mammals Graduated Cylinder Density of acetic anhydride .

08 g/enliven by Lab Manual (page 45) Weight of acetic anhydride. 4 geese #1 in Calculations below Molecular weight of salicylic acid 38. 12 g/nonliving by Lab Manual (page 45) Molecular weight of acetic anhydride 02. 09 g/nonliving by Lab Manual (page 45) Molecular weight of ecstatically acid 80. 16 g/mollies #2 in Calculations below Mass of filter paper + aspirins. 103 gymnastically Balance

Mass of filter appear.

962 gymnastically Balance Mass of aspirins . 141 geese #3 in Calculations below Percent yield of aspirin. 42%See #4 in Calculations

below Calculations: #1)Density = Mausoleum Mass (of acetic anhydride) = Density X Volume = 5. Moll 1.

08 g,'t-ml Mass (of acetic anhydride) - - 5. 4 g #2)Molecular weight of ecstatically acid (CHICHI(S)) = molecular weight of its components. -?molecular weight of 9(C)+8(H)+4(O) = 9(12. 01 smog) + . Ovum) + 4(16. Ovum) Molecular weight of #3)Mass of aspirin = (Mass of filter paper + aspirin) - Mass of filter paper = - 0.

Egg Mass of aspirin = 1. 141 g Calculations continued: #4)# of moles of the limiting reagent = Weight of the limiting reagent (grams) / = weight of salicylic acid / molecular weight of salicylic acid = 1. 49"/ 138. FOMCL = 0. 01085 moles of salicylic acid Theoretical Yield = # of moles of limiting reagent X Of aspirin Molecular weight of aspirin (Ecstatically Acid) = 0.

01085 mol X 180. 16 smog = 1. 953 g Percent actual yield of aspirin = (Actual yield of aspirin/ Theoretical Yield of aspirin) X 100% = (1. IV 100% Percent actual yield of aspirin = 58. 41% #5)# of moles of salicylic acid = 0. 1085 mol (see Calculation #4 above) # of moles of acetic anhydride = weight of acetic anhydride / molecular weight of acetic anhydride = 5.

4 g/ 102. 09 smog -0. 052 mol Since: 0. 052 mol > 0. 01085 mol Discussion Lab Manual Questions (page 44) 1)The limiting reagent is salicylic acid. From the reaction equation (located in the Introduction of this report) one mole of Salicylic acid reacts with one mole of acetic anhydride to form product.

Since there are fewer moles of salicylic

acid relative to acetic anhydride (see Calculation #5 above), the amount of product that can be armed depends on the amount of Salicylic acid, making it the limiting reagent. The theoretical yield is 1. Egg and the percent yield of the aspirin is 58. 41%. The calculations for the theoretical yield and the percent yield can be seen in the results section above. 2)The ecstatically acid is washed with cold water in order to keep the ecstatically in a solid (precipitate) form.

Cold water would lower the kinetic energy of the molecules, slow down their vibration movement, and allow them to crystallize into a solid. This makes it easier for us to filter and collect the aspirin solid. Warm water would increase the kinetic energy of the aspirin molecules, increase their vibration speed, and break their crystal structures. This would dissolve the aspirin into solution and make it much more difficult for us to collect and measure the aspirin. Although aspirin was obtained using rationalizations, the percent yield (58. 1 %) was low.

This due to the many sources of error present in the lab. For example, residual amounts of aspirin were left over on many of the equipment used, especially on stir rods and the inside of flasks. Even with distilled water, the aspirin was difficult to move from the filter paper and glass surfaces in steps three to five in the laboratory annum (Page 44). Some of it was left over on the paper and glass surfaces. A solution for this is taking more care when transferring the product from the different surfaces.

Another solution is that in step 5 of the alba

(page 44 one could try to wash down the aspirin with four small ml portions of water rather than two large 10 ml portions as stated in the lab manual. Another source of error is not allowing enough time for the aspirin to recitalist and precipitate in the ice bath. This would mean that some of the aspirin would be dissolved in solution and not be caught by the filter. A simple solution to this is allowing the aspirin to recitalist for a longer period without disturbance.

One could also add more ice to the ice bath which would cool the solution further and allow precipitate to form faster. An additional source of error can occur during the drying of the filter paper in step 5 of the lab annum (page 44). If one does not dry the paper enough, then the residual moisture on the filter paper could make the weight measurements inaccurate. This Human errors, such as inaccurate measurements due to negligence could also affect the results.

The obvious remedy to this problem is to pay attention and try to do the lab work precisely.

Conclusion Aspirin, also known as ecstatically acid, is derived from an acid catcalled reaction between salicylic acid and acetic anhydride. This crude product has impurities such as unrelated salicylic acid, acetic acid, and sulfuric acid that need to be separated from the pure aspirin. Rationalizations is a process which allows pure aspirin to precipitate out of this crude product. In ideal circumstances, the theoretical yield would be 1. 935 grams of aspirin.

Yet the actual yield was only 1 . 141 grams of aspirin.