It is essential that you know whether the aqueous layer is above or below the organic layer in the separatory funnel, as it dictates which layer is kept and which is eventually discarded….Density.

In the right separating funnel, the aqueous layer is on the top, meaning the organic layer must be more dense than water. Note: CO2 is evolved during extractions using aqueous carbonate or bicarbonate solutions!

The organic product will be soluble in an organic solvent (organic layer) while the inorganic substances will be soluble in water (aqueous layer).

What do I use when to extract? In order to remove an acidic compound from a mixture, a base like NaOH or NaHCO3 is used.

5% sodium bicarbonate is used in extraction to remove the remaining acid present. It does not react with compounds that are sensitive to strong bases or nucleophiles (esters, ketones, aldehydes) because it is a weaker base and a weak nucleophile due to its resonance stabilization.

Sodium bicarbonate is used to neutralize the unreacted carboxylic acid and the catalyst (concentrated sulfuric acid) that are dissolved in the organic layer.

An acid-base extraction is a type of liquid-liquid extraction. It typically involves different solubility levels in water and an organic solvent. The organic solvent may be any carbon-based liqiuid that does not dissolve very well in water; common ones are ether, ethyl acetate, or dichloromethane.

NaHCO3 is a salt of a weak acid, H2CO3, and a strong base,NaOH. Since carbonic acid is a weak acid, it remains undissociated. Hence, the solution becomes basic due to the presence of additional OH- ions produced by hydrolysis.

Very often in the synthesis of a compound or in the isolation of a compound from a natural source, acid-base extractions are used to either directly isolate a desired acidic or basic compound or to remove acidic or basic impurities.

The experiment Mark and his classmates will be working on is very common in the organic chemistry lab, and is called an acid-base extraction. The idea is to leverage the acid-base properties of the compounds in the mixture to help separate them from one another.

What’s the difference between extraction and washing? They’re the same process, but are used for different purposes. Extraction dissolves the material we want and leaves the others behind; washing dissolves the impurities and leaves behind the material we want to isolate.

What is percent recovery and how is it calculated? If you use too much solvent, less of the compound you’re trying to purify recrystallizes (more remains in solution), and you’ll get a low percent recovery. This does not impact the purity of the recovered material.

In the extraction process, a solute is transferred from one phase to another to separate it from unreacted starting materials or impurities. Extraction is also used to facilitate the isolation of a solute from a reaction solvent that is difficult to remove by evaporation, such as a solvent with a high boiling point.

The principle behind solvent extraction is extremely basic. The goal is to use a liquid (solvent) to dissolve (solvate) a target molecule or group of compounds (solute) and to wash them out of the solid plant material. The solvent is then separated from the solute in order to concentrate the solute.

The three most common types of extractions are: liquid/liquid, liquid/solid, and acid/base (also known as a chemically active extraction). The coffee and tea examples are both of the liquid/solid type in which a compound (caffeine) is isolated from a solid mixture by using a liquid extraction solvent (water).

An example of solid-liquid extraction used in every day life is doing your laundry. Your clothes can contain dirt or grime that can be dissolved using water/detergent and removed from the solid clothes. In this example the dirt/contaminants are extracted from the clothes using water as the solvent.

Extraction is the process of selectively removing a compound of interest from a mixture using a solvent. Making tea is a good example of extraction. Water is placed in contact with tea bags and the “tea” is extracted from the tea leaves into the water.

Organic extraction involves the addition of and incubation in multiple different chemical solutions; including a lysis step, a phenol chloroform extraction, an ethanol precipitation, and washing steps. Organic extraction is often used in laboratories because it is cheap, and it yields large quantities of pure DNA.

Not toxic, not flammable.

• Immiscible pair of solvents: water and low polarity organic solvents.
• Good solubility of the target compound.
• Poor solubility of impurities.
• Volatility of the extraction solvent.
• Toxicity and safety properties of the extraction solvent.

Other factors important during solvent selection are viscosity, boiling point, flammability, etc. When a solution is placed in a separatory funnel and shaken with an immiscible solvent, solutes often dissolve in part into both layers.

If crystals do not form, try to scratch the inside of the test tube with a stirring rod. If crystals form, you have found an appropriate recrystallization solvent; if no crystals form, keep looking for the right match between solvent and solute….Selecting a Solvent.

A small amount of the better solvent is added to clarify the solution, and it is allowed to cool for crystallization. Common solvent pairs are water/ethanol, ethyl acetate/hexanes, and ethyl ether/hexanes.

Among the most important are whether the solvents are polar or non-polar, and whether they are protic or aprotic….Solvent Polarity.