Difference Between Separation Of Aspirin And Naphthalene
Separation of mixture of Acetyl salicylic acid (aspirin) and naphthalene
Experiment # 6
A technique called extraction will be demonstrated in this experiment. Extraction relies on the solubility of substances into solvents and the insolubility of the solvents into each other.
In this experiment, three organic compounds (aspirin and naphthalene) will be separated from each other. The two compounds are all soluble in ethyl ether (an organic solvent). By selectively reacting each organic compound, we can make it soluble in water and insoluble in ethyl ether. Since ethyl ether and water are insoluble in each other, they will form two phases and can be separated from each other using a separatory funnel. The reacted organic compound …show more content…
Close the stopcock and repeat the shaking - pressure release procedure until no further pressure build up is noticed. This will indicate the aspirin/NaHCO3 reaction is completed.
Extraction of Aspirin
1. Place the separatory funnel into the ring stand to hold the funnel upright.
2. Remove the stopper from the funnel.
3. Open the stopcock on the separatory funnel and draw off the lower aqueous portion of the liquid into a 125 ml Erlenmeyer flask.
4. Since some of the aqueous solution is still dissolved in the ethyl ether, add an additional 20 ml portion of 5% NaHCO3 and repeat the extraction procedure. Combine this second aqueous portion with the first 5. Place the 125 ml flask into a warm water bath (60 C) and gently heat. This will evaporate any ether still present in the aqueous portion. Do not overheat.
6. Cool the aqueous solution to room temperature.
7. Carefully and slowly, with constant stirring, add 6M HCl with stirring until a pH of 1-2 is indicated by pH paper. The HCl will convert the water soluble salt into the insoluble aspirin. The aspirin will start to precipitate out as the pH is reduced.
8. Vacuum filter the aspirin using a Hirsch funnel and use ice cold water to