This experiment is from the official website of Jimei University
Operation method
extraction experiment
Principle
Extraction: is the use of substances in the two immiscible (or microcapacitance) solvents in the solubility or distribution ratio of the difference to achieve the separation of a purification or purification of an operation. Distribution law: If the volume of the extracted solution is V, the total mass of the solute in the extracted solution is W0, the volume of solvent B used in each extraction is S, after n extractions of the solute in the solvent A residual amount of Wn, then: because the KV ∕ KV + S is constant less than 1 so the larger the n, the smaller the Wn. Generally n = 3~5, i.e., extracted 3~5 times. Purpose of extraction: separation and purification of organic compounds, extraction from the liquid commonly used separatory funnel.
Materials and Instruments
Glacial acetic acid mixed with water Ether NaOH Phenolphthalein indicator Move 1. Specific operations Caveat 1. Check that the glass and piston are tight before using the dispensing funnel, and open the glass before opening the piston. 2. Tilt the funnel upwards and deflate it towards no one. 3. Separate the liquid thoroughly, the upper layer of material released from the upper mouth, the lower layer of material released from the lower mouth. For more product details, please visit Aladdin Scientific website.
Dispensing funnel Conical flask Alkaline burette
(1) Selection of dispensing funnel: 1-2 times larger than the volume of liquid to be treated.
(2) The aqueous solution containing organic matter and the extraction solvent are poured into the separatory funnel sequentially from the upper port.
(3) The extraction solvent is usually 1/3 of the solution volume.
(4) Vent, separate thoroughly, and pour the upper liquid out of the separatory funnel.
(5) The number of extractions is usually 3-5.
(6) The combined extracts are dried by adding a suitable desiccant, then the desiccant is removed and the solvent is evaporated, i.e., the crude product is obtained, and then purified by methods such as recrystallization or distillation.