Question

Need help on providing reactions that describe the acid-base extraction and neutralization processes used in this experiment. Provide a statement of solubility of each starting material and product.

The experiment to be performed this week involves liquid-liquid extraction using a separatory funnel. Read chapter 15 in Zubrick to familiarize yourself with the use of the glassware for extraction and washing. Acid/Base Extraction Liquid-liquid extraction is a technique that can be used to physically separate two substances that have varying solubility properties. Typically an aqueous solution can be extracted with an organic solvent to isolate a compound or vice-versa. The specialized piece of glassware that is employed for these types of separations is called a separatory funnel. In this experiment a mbcture of benzoic acid and naphthalene will be purified using liquid-liquid extraction, more specifically an acid-base extraction. Since both compounds are soluble in ethyl acetate (an organic solvent), and benzoic acid is reactive toward aqueous bases, we can extract the benzoic acid out of the organic solvent into the aqueous solvent and physically separate them. Neutralization of the aqueous solution will yield the purified benzoic acid product that can be characterized using melting point determination benzoic acid naphthalene Experimental Obtain a separatory funnel with stopper from the stockroom. Add 20 mL of ethyl acetate to the separatory funnel followed by 2 g of the organic compound mixture. Swirl the contents of the separatory funnel to dissolve the solids. If any residual compound mixture is stuck to the neck (the ground glass joint) of the separatory funnel wash it down into the funnel using a few milliliters of ethyl acetate. To the separatory funnel add 20 ml of 5% NaOH solution. Insert the stopper into the separatory funnel and invert. Be sure to place the stopper into the funnel correctly. The ground glass loints form a water tight seal so that the solutions cannot escape during extraction, Point the drain away from others and immediately vent the separatory funnel by opening the stopcock. After relieving the pressure, close the stopcock and shake the contents to ensure efficient mixing, Vent periodically to relieve built up pressure. Place the separatory funnel on the ring stand, remove the stopper and allow the solvents to separate. Drain the aqueous laver into a 125 ml Erlenmeyer flask, label as flask A and set aside. Be sure to drain only the lower laver Leave a small amount of the lower layer behind if necessary. Repeat the process of adding sodium hydroxide solution and extracting two additional times. Combine all of the aqueous extracts into the same flask.

Answer 1

on (Napthalene) L t i Benzoic acid), soluble in the Ethyl acetate Naon (ag) → No Reaction. on Maonica lónem Both the above compounds are soluble in the Ethyl art layer and Insoluble in the water. On adding Naoh. ED No Reaction oranges (Soluble in Ethyl acetate) Soluble in salt (Soluble en 1 Ethyl acetate Waten), On- adding Maon ; Sodium benzoate is farmed which is soluble in the water layer; hence get separated. - Recovery of compound on adding Hel (Heutralization) C + Hil(aq) (water soluble) - [ y ott Hace (Precipitates out). Ethylautate soluble" ds Scanned with Scanned with CamScanner