To learn the concept of separating organic compounds by utilizing the concept of acid/base chemistry in so that separation can be done. INTRODUCTION
Using acid base chemistry in the separation of substances can be a quite useful technique in organic chemistry. A basic extraction can be carried out by applying a hot solvent such as water to a dry substance like coffee. This will allow for the extraction of caffeine and flavor from the coffee beans. Acid base chemistry can be useful in separating neutral, basic, and acidic organic substances by controlling the pH of the aqueous layer. In acid base extraction a solvent such as ether is mixed with an aqueous solution of a different pH. This will aid in ionizing the intended compound and separate it from the mixture. Once the molecule is ionized it will precipitate out of the ether solvent and dissolve into the aqueous layer. The aqueous layer can then be removed and the pure substance can be obtained through crystallization.
In this week's lab a mixture of carboxylic acid, phenol, and a neutral substance were separated from an ether solution. First, the carboxylic acid was ionized with a weak base and removed. A strong base was then applied to the mixture to allow the phenol to ionize and precipitate into the aqueous layer. This layer of aqueous solution was then extracted which left the neutral compound in the ether solvent. The three separated substances were then crystallized for melting point and identification. PROCEDURE
Isolation a neutral compound from a mixture containing an acid impurity 1. 0.24grams of unknown sample and 0.12 grams benzoic acid was weighted and placed in a test tube. 2. 10ml of ether was added to the mixture and was shakes to dissolve completely the mixture. 3. The solution then transferred to 125 ml separatory funnel and 5ml of 1M NaOH was added, with the cap tight, the layers was mix by swirling and shaking for 30 seconds. Pressure was vent by...