SEPARATIONS OF ORGANIC COMPOUNDS

The evolution of organic chemistry into a modern experimental science has occurred primarily because pure organic compounds can be isolated from the rich sources of organic compounds found in nature. Natural sources such as plants, coal and petroleum contain complex mixtures of organic compounds. The separation of these complex mixtures into their individual components is performed through the use of techniques based on differences in physical properties of organic compounds. Physical properties such as solubilities and boiling points are translated into viable, procedures for the selective isolation of particular materials from their environment.

       The separation methods that are of greatest importance in organic chemistry are extraction, crystallization (filtration), distillation and chromatography. Extraction and crystallization techniques depend on the solubility characteristics of organic compounds. Separations by distillation rely on differences in boiling points among the components of a mixture. Differences in the abilities of chemicals to adhere to surfaces (adsorption) are basic to chromatographic separations. Each of these methods is built upon a distinguishable physical difference among the components of a mixture.

We can separate compounds that differ in their solubility properties, boiling points, or adsorptivities by using separation techniques that are based on these physical differences. Frequently chemical reactions, particularly acid-base reactions are employed to produce dramatic physical differences between components of mixtures.

VOCABULARY:

science	-nauka
occur	- występować
primarily	- głównie
pure	- czysty
compound	- związek
isolated	- wyodrębniony, wydzielony
sources	- źródła
plants	- rośliny
coal	- węgiel
petroleum	- ropa naftowa
complex	- zespół
mixtures	- mieszaniny
separation	- rozdzielanie
component	- komponenty
techniques	- techniki
physical	- fizyczne
properties	- właściwości
solubility	- rozpuszczanie
boiling point	- temperatura wrzenia
abilities	- zdolności
adhere	- przywieranie
surfaces	- powierzchnia
adsorption	- adsorpcja
chromatography	- chromatografia
adsorptivity	- adsorpcyjność                                                    - reakcje
reactions	- reakcje
acid	- kwas
base	- zasada
dramatic	- dramatyczny