Synthetic Techniques in Organic Chemistry

Crystallization is one of the important methods for the purification of the reaction product. The method consists of heating the crude product with suitable solvent. (Substances sparingly soluble in the solvent in cold and highly soluble on warming) and then filtered hot to remove any insoluble material. Upon cooling, the substance generally in pure form crystallizes out.This video will help how to do the recrystallization in the lab.Thank you
DISTILLATION

Distillation is a widely used method for separating mixtures based on differences in the conditions required to change the phase of components of the mixture. To separate a mixture of liquids, the liquid can be heated to force components, which have different boiling points, into the gas phase. The gas is then condensed back into liquid form and collected. Repeating the process on the collected liquid to improve the purity of the product is called double distillation. Although the term is most commonly applied to liquids, the reverse process can be used to separate gases by liquefying components using changes in temperature and/or pressure.This video wil help you to perform Distillation in your Lab.Thank you

THIN LAYER CHROMATOGRAPHY

Thin-layer chromatography (TLC) is a very commonly used technique in synthetic chemistry for identifying compounds, determining their purity and following the progress of a reaction. It also permits the optimization of the solvent system for a given separation problem. In comparison with column chromatography, it only requires small quantities of the compound (~ng) and is much faster as well.Watch this video to learn more.Thank you

EXTRACTION

Liquid-liquid extractions using a separatory funnel are essentially the only kind of extraction performed in the organic teaching labs. The "liquid-liquid" phrase means that two liquids are mixed in the extraction procedure. The liquids must be immiscible: this means that they will form two layers when mixed together, like oil and vinegar do in dressing. Some compounds are more soluble in the organic layer (the "oil") and some compounds are more soluble in the aqueous layer (the "vinegar").

COLUMN CHROMATOGRAPHY


In column chromatography, the stationary phase, a solid adsorbent, is placed in a vertical glass (usually) column and the mobile phase, a liquid, is added to the top and flows down through the column (by either gravity or external pressure). Column chromatography is generally used as a purification technique: it isolates desired compounds from a mixture.

The mixture to be analyzed by column chromatrography is applied to the top of the column. The liquid solvent (the eluent) is passed through the column by gravity or by the application of air pressure. An equilibrium is established between the solute adsorbed on the adsorbent and the eluting solvent flowing down through the column. Because the different components in the mixture have different interactions with the stationary and mobile phases, they will be carried along with the mobile phase to varying degrees and a separation will be achieved. The individual components, or elutants, are collected as the solvent drips from the bottom of the column.

Column chromatography is separated into two categories, depending on how the solvent flows down the column. If the solvent is allowed to flow down the column by gravity, or percolation, it is called gravity column chromatography. If the solvent is forced down the column by positive air pressure, it is called flash chromatography, a "state of the art" method currently used in organic chemistry research laboratories The term "flash chromatography" was coined by Professor W. Clark Still because it can be done in a “flash."WATCH THE VIDEO..