CHEMISTRY GLOSSARY

swamp gas    →   močvarni plin

Swamp gas is a gas which develops by rottening of organic matter with no presence of air at all, e.g. at bottom of the swamp. The chief component is methane (CH₄).

vapour pressure lowering    →   snižavanje tlaka pare

Vapour pressure is a colligative property of solutions. The vapour pressure of a solution is always lower than the vapour pressure of the pure solvent. Ratio of solution to pure solvent vapour pressures is approximately equal to the mole fraction of solvent in the solution.

waste water    →   otpadna voda

Waste waters are waters which pour down from housing, public or industrial plants and are polluted with mineral and organic substances and microorganisms.

white spirit    →   bijeli špirit

White spirit (mineral spirits, petroleum spirits) is a paraffin-derived clear, transparent liquid which is a common organic solvent used in painting and decorating.

paper chromatography    →   papirna kromatografija

Paper chromatography is one of the types of chromatography procedures which runs on a piece of specialized paper. It is a planar chromatography systems wherein a cellulose filter paper acts as a stationary phase on which separation of compounds occurs. The edge of the paper is immersed in a solvent, and the solvent moves up the paper by capillary action.

para position    →   para položaj

Para position in organic chemistry is the one in which there are two same functional groups tied to a ring of benzene in the position 1 and 4. The abbreviation p- is used, for example, p-Hydroquinone is 1,4-dihydroxybenzene.

peptide    →   peptid

Peptides are amides derived from two or more amino acids (the same or different) linked by peptide bonds. These bonds are formed by the reaction between adjacent carboxyl (-COOH) and amino (-NH₂) groups with the elimination of water.

phosphorus    →   fosfor

Phosphorus was discovered by Hennig Brandt (Germany) in 1669. The origin of the name comes from the Greek word phosphoros meaning bringer of light. White phosphorus is white to yellow soft, waxy phosphorescent solid with acrid fumes. Toxic by inhalation, ingestion, or skin contact. Red phosphorus is powdery, non-flammable and non-toxic. Phosphorus is found most often in phosphate rock. Pure form is obtained by heating a mixture of phosphate rock, coke and silica to about 1450 °C. Used in the production of fertilizers and detergents. Some is used in fireworks, safety matches and incendiary weapons. Phosphorus is also important in the production of steels, phosphor bronze and many other products.

potassium    →   kalij

Potassium was discovered by Sir Humphry Davy (England) in 1807. The origin of the name comes from the Arabic word qali meaning alkali (the origin of the symbol K comes from the Latin word kalium). It is soft, waxy, silver-white metal. Fresh surface has silvery sheen. Quickly forms dull oxide coating on exposure to air. Reacts strongly with water. Reacts with water to give off flammable gas. Reacts violently with oxidants. Occurs only in compounds. Potassium is found in minerals like carnallite [(KMgCl₃)·6H₂O] and sylvite (KCL). Pure metal is produced by the reaction of hot potassium chloride and sodium vapours in a special retort. Used as potash in making glass and soap. Also as saltpetre, potassium nitrate (KNO₃) to make explosives and to colour fireworks in mauve. Vital to function of nerve and muscle tissues.

retardation factor    →   faktor zaostajanja

Retardation factor, R_F, (in planar chromatography) is a ratio of the distance travelled by the centre of the spot to the distance simultaneously travelled by the mobile phase:

The R_F value is characteristic for any given compound on the same stationary phase using the same mobile phase for development of the plates. Hence, known R_F values can be compared to those of unknown substances to aid in their identifications.