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Heating Under Reflux Synthesis of Salicylic Acid from Wintergreen Oil 02/03/2021 Alin

Purpose: The purpose of this experiment was the synthesis of salicylic acid from Wintergreen Oil and find out whether or not it differs from salicylic acid made from benzene. The synthetic form was expected to be the same as that made from natural Wintergreen Oil. Salicylic acid was synthesized through reflux, vacuum filtration and recrystallization process. The new synthesized salicylic acid was dried to constant mass and its melting point was compared to that of salicylic acid made from benzene. Procedure: • 2.00 milimoles of methyl salicylate was heated in a boiling flask on top of a heated mantle. • 2.5 mL of 6M sodium hydroxide was added into the flask and heated until it was complete dissolved. • After heating for 30 minutes, approximately 2.7mL of 3M sulfuric acid was added until the pH was lowered to 2. • The mixture was allowed to cool and salicylic acid was collected by vacuum filtration. • Recrystallized, dried to constant mass.

• The mass was taken and the melting point was measured. Conclusion: In the experiment salicylic acid synthesized from two different materials, wintergreen oil and benzene were compared. Firstly the acid was synthesizing from the wintergreen oil by heating through reflux using sodium hydroxide. Sulfuric acid was added to the sodium salicylate in order to produce salicylic acid. Salicylic acid was then filtrated and recrystallized to get pure salicylic acid. Finally, the melting point of the salicylic acid was compared to salicylic acid synthesized from benzene. The melting point of the salicylic acid synthesized from wintergreen oil was rather accurate because the range was from 157. °C - 159.1°C and the melting point of salicylic acid synthesized from benzene was between 159 °C - 160°C. The melting point of the product is only slightly lower than the actual value. This suggests that the product was relatively pure. The percent yield produced was 54.7 %. End of chapter questions: 1. What is the percent yield of this reaction. Show all work 260uL/1000=0.260mL x 1.174g/1mL=0.305g MS x 1mol MS/152.1g MS x 1Mol SA/1 Mol MS x138.1g SA/1mol SA=0.276g SA 0.151g/0.276g x100=54.7% Methyl salicylate molecular weight =152.1g/mol Salicylic acid molecular weight = 138.1g/mol

2. What is the point of doing a reaction under reflux conditions? Reflux conditions helps keep a solution heated in a controlled manner, and get solvent into a boiling point, without losing any solvent. 3. Why is it important to cool the condenser? A cool condenser allows vapor from the reaction mixture to be continually heated with a minimal loss of solvent. The cooled vapors condense and drip back down into the flask....