CHEMISTRY GLOSSARY

cerium    →   cerij

Cerium was discovered by Martin Heinrich Klaproth (Germany) and by Jöns Jacob Berzelius (Sweden) in 1803 and Wilhelm von Hisinger (Germany) in 1814. Named after the asteroid Ceres this discovered two years before the element. It is malleable, ductile, iron-grey metal. Tarnishes in air; reacts easily with water. Dissolves in acids; ignites when heated. Metal ignites and burns readily. Strong reductant. Cerium is most abundant rare earth metal. Found in many minerals like monazite sand [Ce(PO₄)]. Its oxides are used in the optics and glass-making industries. Its salts are used in the photography and textile industry. Used in high-intensity carbon lamps and as alloying agents in special metals.

cobalt    →   kobalt

Cobalt was discovered by Georg Brandt (Germany) in 1735. The origin of the name comes from the German word kobald meaning goblin or evil spirit. It is hard, ductile, lustrous bluish-grey metal. Surfaces stable in air. Reacts over time with dilute acids. It has remarkable magnetic properties. Cobalt occurs in compounds with arsenic and sulfur as in cobaltine (CoAsS) and linneite (Co₃S₄). Pure cobalt is obtained as a by-product of refining nickel, copper and iron. Used in many hard alloys; for magnets, ceramics and special glasses. Radioactive cobalt-60 is used in cancer therapy.

contact procedure    →   kontaktni postupak

Contact procedure is an industrial procedure used for the production of sulphuric acid, where a dry and clean sulphur dioxide and air go over a catalyst made of vanadium pentoxide at 450 °C by which sulphur trioxide is gained, then we add concentrated sulphuric acid by which we obtain smoking sulphuric acid which is now diluted to sulphuric acid.

ricin    →   ricin

Ricin is a toxin derived from the castor bean. It can be spread in aerosol or liquid form. It causes blood poisoning and leads to the collapse of the circulatory system and a slow death.

spontaneously combustible    →   samozapaljivi materijal

Spontaneously combustible materials are materials that can ignite without an external source of heat. Heat sufficient to reach the ignition temperature may be generated by reaction with oxygen in the air, by the absorption of moisture, from heat generated during processing, or even from radioactive decay.

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).

tempering    →   kaljenje

Tempering is a rapid cooling of metals (often steels) from a suitable elevated temperature, thus changing its properties, e.g. steel becomes harder. This is generally accomplished by immersion in water, oil, polymer solution, or salt, although forced air is sometimes used.

thermionic emission    →   termionska emisija

Thermionic emission is the boiling off of electrons from heated metals. It gives a source of electrons for cathode ray tubes.

Contat-Gockel’s valve    →   Contat-Gockelov ventil

Contat-Göckel’s valve is used for maintenance of inert atmosphere in a flask. The valve is filled with a saturated solution of sodium bicarbonate (NaHCO₃) so that the end of the tube is covered. Solution inside the valve keeps the flask contents away from the oxygen influence from air. If low pressure is created inside the flask (when the flask is cooled), the solution will penetrate inside it from funnel and in a reaction with acid CO₂ is generated which fills up the flask.

Solution from the funnel will keep penetrating until CO₂ pressure in the flask is equalised with the outer pressure.

copper    →   bakar

Copper has been known since ancient times. The origin of the name comes from the Latin word cuprum meaning the island of Cyprus famed for its copper mines. It is malleable, ductile, reddish-brown metal. Resistant to air and water. Exposed surfaces form greenish carbonate film. Pure copper occurs rarely in nature. Usually found in sulfides as in chalcopyrite (CuFeS₂), coveline (CuS), chalcosine (Cu₂S) or oxides like cuprite (Cu₂O). Most often used as an electrical conductor. Also used in the manufacture of water pipes. Its alloys are used in jewellery and for coins.