Organic Acid Lab Report

DESCRIPTION
 A simple reaction, followed by isolation of the desired product from the solution, will illustrate a typical application of extraction.
 Some organic acids are liquid and are soluble in water as indicated. The sodium salts of these acids are ionic compounds that are also very soluble in water. If an aqueous solution of one such salt is acidified with a strong mineral acid, the much weaker organic acid is produced.
 The weak organic acid is largely un-ionized in the aqueous solution.
 No apparent change is observed when the reaction is carried out because the solutions of the starting materials and the products are colorless. The organic acid is soluble in water and thus, does not separate. It is necessary to extract the

 Dissolve the salt in 60 ml of tap water. Add 30 ml 6 M Hcl and stir the mixture with a glass rod.
 Add 12 g solid Nacl to the solution and stir the mixture for about 2 minutes.
 Support a 250 ml separatory funnel on a ring, making sure that the stopcock is closed and that a clean beaker is placed beneath the exit tube. Transfer the aqueous solution from the beaker to the separatory funnel. Do not transfer any un-dissolved sodium chloride in the beaker to the funnel.
Extract the aqueous solution with dichloromethane in the following manner:
a) Add 20 ml of solvent to the solution in the separatory funnel.
b) Place the plastic stopper (NOT greased) in the neck of the funnel. Shake
c) Drain the lower aqueous layer through the stopcock into the same 250 ml beaker in which the solution had been prepared in steps above.
d) Pour the upper solvent layer through the neck of the funnel into a clean 125 ml Erlenmeyer flask. Return the aqueous solution from the 250 ml beaker to the separatory funnel. Add another fresh 20 ml of solvent to the funnel and again extract the aqueous solution as you did in b)

flask as the distillation flask. Use a 125 ml Erlenmeyer flask as the receiver.
• Remove the thermometer and adapter from the assembly and place along-stem funnel in the still pot. Insert a small plug of absorbent cotton at the top of the funnel stem.
• Carefully decant the solvent solution from the drying agent through the funnel into the flask. Rinse the Erlenmeyer flask with about 10 ml of solvent and pour the solvent through the funnel, too. Remove the funnel, add two or three boiling chips and reattach the thermometer and adapter to the still pot.
• Discard the magnesium sulfate remaining in the Erlenmeyer flask by dissolving it in tap water and pouring the solution down the drain.
• Before beginning the distillation, weigh a clean, dry 1 narrow mouth screw cap bottle on a balance. Remove the cap of the bottle, and insert the clean, dry plastic long-stem funnel in the neck of the bottle. Set aside until needed.
• Slowly distill the solvent from the solution.
• Pour the solvent into the recovered solvent container.
• Allow the crude propionic acid (normal b.p., 142oC) in the still pot to cool. Once cool, decant into an appropriately labeled sample